staple has 4 distinct synonyms spread across 3 of its 7 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is unstaple.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a natural fiber (raw cotton, wool, hemp, flax) that can be twisted to form yarn
“staple fibers vary widely in length”
material suitable for manufacture or use or finishing
a short U-shaped wire nail for securing cables
paper fastener consisting of a short length of U-shaped wire that can fasten papers together
1 of the 7 recorded senses carries no synonym, antonym or related term, so it is not shown above. Every sense, with its definition and examples, is on the full entry for staple.
Synonyms, antonyms and the broader and narrower relations for staple come from Princeton University’s WordNet. Full sources and licences.