Evolutionary means happening by slow development over generations. Change so gradual that no single step is visible.
Biology owns the precise sense, since evolutionary biology studies how species change through natural selection over enormous stretches of time. Everyday use borrows the pace rather than the mechanism, so describing a design as evolutionary rather than revolutionary means it improves on what came before instead of replacing it, and that contrast is the commonest way the word appears outside science.
1adjectiveevolutionaryRelating to the gradual development of species over generations.
“There is a clear evolutionary advantage to sharing food.”
2adjectiveproceedingProceeding by gradual change rather than sudden replacement.
“The new model is evolutionary rather than revolutionary.”
Latin
ēvolūtiō — the act of unrolling, unfolding or opening (of a book)
English
evolution
English, today
evolutionary
Built from
From evolution + -ary. evolution Borrowed from Latin ēvolūtiō (“the act of unrolling, unfolding or opening (of a book)”), from ēvolūtus, perfect passive participle of ēvolvō (“unroll, unfold”), from ex + volvō (“roll”). Compare typologically vývoj, развој, разви́ть, развива́ть, разви́ться, развива́ться, разви́тие, related to viti (whence vít, вить).
Etymology from Wiktionary, CC BY-SA