tinker has 11 distinct synonyms spread across 4 of its 6 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 person who enjoys fixing and experimenting with machines and their parts
formerly a person (traditionally a Gypsy) who traveled from place to place mending pots and kettles and other metal utensils as a way to earn a living
do random, unplanned work or activities or spend time idly
“The old lady is usually mucking about in her little house”
Synonyms, antonyms and the broader and narrower relations for tinker come from Princeton University’s WordNet. Full sources and licences.