transitive verb

1. to build up or expand (a business, industry, etc.) to make stronger or more effective; strengthen (muscles) to bring (something latent or hypothetical) into activity or reality to cause (one's personality, a bud, etc.) to unfold or evolve gradually to make (housing, highways, etc.) more available or extensiveChess to position (chessmen or a chessman) strategically in the early stages of a gameMusic to elaborate (a theme) as by rhythmic or melodic changesPhotog.
   1. to immerse (an exposed film, plate, or printing paper) in various chemical solutions in order to make the picture visible
   2. to make (a picture) visible by doing this
2. to make (a theme or plot) known gradually to explain more clearly; enlarge uponGeom. to change the form of (a surface); esp., to flatten out (a curved surface)Math. to work out in detail or expand (a function or expression)

Etymology: Fr développer < OFr desveloper < des- (L dis-), apart + voloper, to wrap, prob. OIt viluppo, a bundle < ? faluppa, bundle of straw; infl. by L volvere, to roll

intransitive verb

1. to come into being or activity; occur or happen
2. to become larger, fuller, better, etc.; grow or evolve, esp. by natural processes
3. ☆ to become known or apparent; be disclosed
4. to progress economically, socially, and politically from an underdeveloped condition the developing nations