Prefixes (R to U)

Prefixes in English R to U

List of common prefixes-R to U 


: once more; afresh; anew
: (also red-) in return; mutually; in opposition
: behind or after
: with frequentative or intensive force
 : in a withdrawn state  : back and away; down : with negative force

reactivate = to cause sth to start working or happening again : to activate sth again
reappraise = to make a new judgment about the value of (something)
      :to think about sth again to decide whether you should change your opinion
revert = to go back or return to (an earlier state, condition, situation, etc.)
resemble = to look or be like (someone or something)
repel = to keep sth out or away : to force (an enemy, etc.) to stop an attack and turn away
resistance = refusal to accept something new or different (-from)
     : effort made to stop or to fight against sth or sb
     : the ability to prevent something from having an effect
remain = to be left when the other parts are gone or have been used
     : to be sth that still needs to be done, dealt with, etc.
relic = something that is from a past time, place, culture, etc. ― often + of or from
recede = to move away gradually : to become smaller or weaker
rebuff = formal : to refuse (something, such as an offer or suggestion) in a rude way


: apart; without

secede= to separate from a nation or state and become independent
seclude= to keep (someone) away from other people
secure= protected from danger or harm : providing protection from danger or harm
   : feeling safe and free from worries or doubt : confident
   : firmly attached :not in danger of being lost or taken away


: half
  ; occurring or appearing twice in a specified period
: partly; in some degree or particular
  : almost 

semicircle = half of a circle
semilegendary= having historical foundation but elaborated in legend
semiannual= happening or produced every six months or twice in each year
semidarkness= partial darkness
semiconscious= incompletely conscious : imperfectly aware or responsive

 sub- (Also suc-, suf-, sug-, sup-, sur-, sus-) 


: under, beneath
: subsidiary, secondary
: almost, nearly

submarine= a ship that can operate underwater
subset=a group of things, people, etc., that is part of a larger group
subway= a system of underground trains in a city
   Brit : a road for walking under a road, set of railroad tracks, etc. : underpass
subtitle= a secondary or explanatory title
   : words that appear on the screen during a movie, etc. and that are translations of what the actors are saying
subjugate= formal : to defeat and gain control of sb or sth by the use of force
   : to conquer and gain the obedience of (a group of people, a country, etc.)
succumb= somewhat formal 1 : to stop trying to resist something
  : to die
suggest= to mention (sth) as a possible thing to be done, used, thought about, etc.
  : to say that (someone or something) is good or deserves to be chosen : recommend
  : to show that sth is likely or true : to indicate sth usually without showing it in a direct or certain way   : to say (something) in an indirect way ;imply

suppress= to end or stop (something) by force
  : to keep (something) secret : to not allow people to know about or see (something)
  : to not allow yourself to feel, show, or be affected by (an emotion)
  : to slow or stop the growth, development, or normal functioning of (something)

suspend= : to force sb to leave a job, position, or place for a usually short period of time as a form of punishment
  : to stop (something) for a usually short period of time
  : to make (something) happen later : to delay (something)
  : to hang something so that it is free on all sides except at the point of support

substance= a material of a particular kind
  : the quality of being meaningful, useful, or important (noncount)
  : the most basic or necessary part or quality of something : essence (noncount)
  : a drug that is considered harmful and whose use is controlled by law or made illegal 

 syn-, sym-, syl-  

: united; acting or considered together

synonym= a word that has the same meaning as another word in the same language
synchronize= to cause (things) to agree in time or to make (things) happen at the same time and speed

symmetry=the quality of something that has two sides or halves that are the same or very close in size, shape, and position : the quality of having symmetrical parts

synergy= the increased effectiveness that results when two or more people or businesses work together

synchronicity= the quality or fact of being synchronous
synesthesia= the production of a sense impression relating to one sense or part of the body by stimulation of another sense or part of the body.


: across, beyond
: through

transnational= operating in or involving more than one country
transatlantic= going across the Atlantic Ocean : located on or coming from the other side of the Atlantic Ocean
transfer= to move (someone or something) from one place to another
  : to cause (a disease, virus, etc.) to move from one living thing to another : transmit
  : to use (something, such as an idea, a skill, etc.) for a new or different purpose
  : to stop going to one school and begin going to another
  : to move to a different place or job for the same employer
  : to change from one plane, bus, train, etc., to another while traveling

transit = the act of moving people or things from one place to another
  : to send (information, sound, etc.) in the form of electrical signals to a radio, television, etc.
  : to give or pass (information, values, etc.) from one person to another
  : to cause (a virus, disease, etc.) to be given to others
  : to allow (light, heat, etc.) to pass through
transport= to carry (someone or something) from one place to another 


: beyond; on the other side of; trans-
: extreme; to an extreme degree; super-

ultraviolet= used to describe rays of light that cannot be seen and that are slightly shorter than the rays of violet light
ultrasonic= used to describe sounds that are too high for humans to hear; ultrasound
ultrasecret= extremely secret 


: denoting the reversal or cancellation of an action or state
: denoting deprivation, separation, or reduction to a lesser state

unhappy= sad, depressed, or disappointed : not happy
unbreakable= not able to be broken : not breakable
unmask= to reveal the true identity or nature of (someone or something)
unhand= release (someone) from one's grasp
unsettle= to make (someone) nervous, worried, or upset


: below; beneath
: insufficiently; incompletely

underwear= clothing that is worn next to your skin and under other clothing
undercover= done or working in a secret way in order to catch criminals or collect information
undernourished= not getting enough food or not getting enough healthy food for good health and growth
underdeveloped= not developed to a normal size or strength
undersecretary= a high-ranking government official who serves under a department secretary or other high official 


: (added to verbs and their derivatives) upward
: (added to nouns) denoting (direction of) motion up
: (added to nouns) higher

uptight= nervous or worried and tending to become upset about sth that does not make other people upset
upturned= turned so that the bottom part is on top : turned upside down
uphill= toward the top of a hill or mountain
update= to change (something) by including the most recent information
upland= a region of high land especially far from the sea ― usually plural