Relating to or having the quality of speeding something up; tending to accelerate.
From accelerate + -ive (forming adjectives meaning 'having the quality of'). The Latin root accelerare combines ad- (to) and celer (swift, quick).
Scientific and technical fields love -ive adjectives because they sound more precise and formal than simple 'fast' or 'quick'—'accelerative forces' sounds more authoritative in a physics paper than 'speeding-up forces'!
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