leg has 6 distinct synonyms spread across 3 of its 9 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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 human limb; commonly used to refer to a whole limb but technically only the part of the limb between the knee and ankle
a structure in animals that is similar to a human leg and used for locomotion
one of the supports for a piece of furniture
a part of a forked or branching shape
“he broke off one of the branches”
the limb of an animal used for food
a cloth covering consisting of the part of a pair of trousers that covers a person's leg
(nautical) the distance traveled by a sailing vessel on a single tack
a section or portion of a journey or course
“then we embarked on the second stage of our Caribbean cruise”
Synonyms, antonyms and the broader and narrower relations for leg come from Princeton University’s WordNet. Full sources and licences.