dip has 16 distinct synonyms spread across 9 of its 23 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.
stain an object by immersing it in a liquid
take a small amount from
“I had to dip into my savings to buy him this present”
slope downwards
“Our property dips towards the river”
place (candle wicks) into hot, liquid wax
immerse in a disinfectant solution
“dip the sheep”
plunge (one's hand or a receptacle) into a container
“He dipped into his pocket”
scoop up by plunging one's hand or a ladle below the surface
“dip water out of a container”
a depression in an otherwise level surface
“there was a dip in the road”
(physics) the angle that a magnetic needle makes with the plane of the horizon
Synonyms, antonyms and the broader and narrower relations for dip come from Princeton University’s WordNet. Full sources and licences.
a thief who steals from the pockets or purses of others in public places
tasty mixture or liquid into which bite-sized foods are dipped
a sudden sharp decrease in some quantity
“a drop of 57 points on the Dow Jones index”
a candle that is made by repeated dipping in a pool of wax or tallow
a gymnastic exercise on the parallel bars in which the body is lowered and raised by bending and straightening the arms