filling has 4 distinct synonyms spread across 2 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.
flow into something (as a container)
Synonyms, antonyms and the broader and narrower relations for filling come from Princeton University’s WordNet. Full sources and licences.
a food mixture used to fill pastry or sandwiches etc.
(dentistry) a dental appliance consisting of any of various substances (as metal or plastic) inserted into a prepared cavity in a tooth
“when he yawned I could see the gold fillings in his teeth”
the act of filling something