either the right or left half of the body

sign - v. to write one's name; n. a mark or shape used to mean something; evidence¹ that something exists or will happen; a flat piece of material with writing that gives information

signal² - v. to send a message by signs; n. an action or movement that sends a message

silence - v. to make quiet; to stop from speaking or making noise; n. a lack of noise or sound

silver - n. a valued white metal

similar - ad. like something else but not exactly the same

simple - ad. easy to understand or do; not difficult or complex³

since - prep. from a time in the past until now ("I have known⁴ her since we went to school together.")

sing - v. to make music sounds with the voice

single - ad. one only

sink - v. to go down into water or other liquid

sister - n. a female⁵ with the same father or mother as another person

sit - v. to rest on the lower⁶ part of the body without the support of the legs; to become seated

situation - n. the way things are during a period of time

size - n. the space occupied by something; how long, wide or high something is

skeleton⁷ - n. all the bones of a human or other animal together in their normal positions skill - n. the ability gained from training or experience

skin - n. the outer covering of humans and most animals

sky - n. the space above the earth

slave⁸ - n. a person owned or controlled by another

sleep - v. to rest the body and mind with the eyes closed

slide - v. to move smoothly⁹ over a surface

slow - v. to reduce the speed of; ad. not fast in moving, talking or other activities

small - ad. little in size or amount; few in number; not important; opposite large

smash¹⁰ - v. to break or be broken into small pieces by force; to hit or move with force

smell - v. to sense through the nose; n. something sensed by the nose ("the smell of food cooking")

smoke - v. to use cigarettes or other tobacco¹² products by burning them and breathing in the smoke; n. that which can be seen rising into the air like a cloud from something burning

smooth - ad. having a level surface; opposite rough¹¹

snow - n. soft, white pieces of frozen¹³ water that fall from the sky, usually in winter or when the air temperature is very cold

so - ad. in such a way that ("He held the flag so all could see it."); also; too ("She left early, and so did we."); very ("I am so sick."); as a result ("They were sick, so they could not come."); conj. in order that; for the purpose of ("Come early so we can discuss the plans.")

social - ad. of or about people or a group

soft - ad. not hard; easily shaped; pleasing to touch; not loud

soil - n. earth in which plants grow

soldier - n. a person in the army

solid¹⁴ - ad. having a hard shape with no empty spaces inside; strong; not in the form of a liquid or gas

solve - v. to find an answer; to settle¹⁵ some - ad. of an amount or number or part not stated; not all