tip has 29 distinct synonyms spread across 10 of its 14 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.
mark with a tip
“tip the arrow with the small stone”
a relatively small amount of money given for services rendered (as by a waiter)
Synonyms, antonyms and the broader and narrower relations for tip come from Princeton University’s WordNet. Full sources and licences.
a V shape
“the cannibal's teeth were filed to sharp points”
the top or extreme point of something (usually a mountain or hill)
“the view from the peak was magnificent”