seed has 9 distinct synonyms spread across 4 of its 13 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.
help (an enterprise) in its early stages of development by providing seed money
place (seeds) in or on the ground for future growth
“She sowed sunflower seeds”
distribute (players or teams) so that outstanding teams or players will not meet in the early rounds
sprinkle with silver iodide particles to disperse and cause rain
“seed clouds”
Synonyms, antonyms and the broader and narrower relations for seed come from Princeton University’s WordNet. Full sources and licences.
a mature fertilized plant ovule consisting of an embryo and its food source and having a protective coat or testa
anything that provides inspiration for later work
the thick white fluid containing spermatozoa that is ejaculated by the male genital tract