sure - ad. very probable¹; with good reason to believe; true without question

surface - n. the outer side or top of something ("The rocket landed on the surface of the moon.")

surplus² - n. an amount that is more than is needed; extra; ("That country has a trade surplus. It exports more than it imports.")

surprise - v. to cause a feeling of wonder because something is not expected; n. something not expected; the feeling caused by something not expected

surrender³ - v. to give control of oneself or one's property⁴ to another or others; to stop fighting and admit defeat

surround - v. to form a circle around; to be in positions all around someone or something

survive - v. to remain alive during or after a dangerous situation

suspect - v. to imagine or believe that a person is guilty⁵ of something bad or illegal⁶; n. a person believed to be guilty

suspend⁷ - v. to cause to stop for a period of time

swallow - v. to take into the stomach through the mouth

swear in - v. to put an official into office by having him or her promise to carry out the duties of that office ("The chief justice will swear in the president.")

sweet - ad. tasting pleasant, like sugar

swim - v. to move through water by making motions⁸ with the arms and legs

sympathy⁹ - n. a sharing of feelings or emotions with another person, usually feelings of sadness

system - n. a method of organizing or doing something by following rules or a plan; a group of connected things or parts working together for a common purpose or goal