1. (a.) Falling or rushing headlong; rushing swiftly, violently, or recklessly\; moving precipitately.

2. (a.) Unexpectedly or foolishly brought on or hastened; rashly hurried; hasty; sudden; reckless.

3. (n.) Any force or reagent which causes the formation of a precipitate.

abrupt accident-prone breakneck breathless careless desperate devil-may-care electrifying furious harum-scarum hasty headlong hotheaded hurried impetuous impulsive mad nerve-shattering overeager overenthusiastic overzealous panting precipitate precipitous quick rash reckless rushing shocking slap-bang slapdash speedy startling sudden surprising swift unanticipated unexpected unforeseen unlooked-for unpredicted wanton wild