the smallest unit of a chemical element

smallest part of something

(a part of) a tool used for boring or drilling holes

tiny piece

small round mark (as over the letter i and j)

tiny mark, drop

the small, hard seed of food plants such as wheat and rice

seed, piece

a note with half the value of a semibreve

bit

a sharp end (of a pin, pencil etc); a marked place or position in space or time; a small dot (as if) made by the point of a pencil etc; a main piece of information, idea or thought in an argument

speck

a mark, sign etc showing that a person or thing has been present, that something has existed or happened; a very small amount; to draw along, follow, the course, outline etc of (something)

evidence; small bit