develop has 22 distinct synonyms spread across 11 of its 21 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.
create by training and teaching
“The old master is training world-class violinists”
be gradually disclosed or unfolded; become manifest
“The plot developed slowly”
grow, progress, unfold, or evolve through a process of evolution, natural growth, differentiation, or a conducive environment
“A flower developed on the branch”
make visible by means of chemical solutions
“Please develop this roll of film for me”
superimpose a three-dimensional surface on a plane without stretching, in geometry
move one's pieces into strategically more advantageous positions
“Spassky developed quickly”
move into a strategically more advantageous position
“develop the rook”
elaborate by the unfolding of a musical idea and by the working out of the rhythmic and harmonic changes in the theme
“develop the melody and change the key”
expand in the form of a series
“Develop the function in the following form”
Synonyms, antonyms and the broader and narrower relations for develop come from Princeton University’s WordNet. Full sources and licences.