Present participle of accelerate; increasing in speed or rate of progress.
From Latin 'acceleratus,' from 'accelerare' meaning to hasten, derived from 'ad-' (toward) and 'celerare' (to quicken), from 'celer' (swift). The physics sense developed in the 17th century.
Einstein showed us that acceleration and gravity are fundamentally the same phenomenon - when you're in an accelerating elevator, you can't tell if you're speeding up or if gravity has suddenly gotten stronger.
Complete word intelligence in one call. Free tier — 50 lookups/day.