- hasty, overhasty, precipitate, precipitant, precipitous - done with very great haste and without due deliberation; "hasty marriage seldom proveth well"- Shakespeare; "hasty makeshifts take the place of planning"- Arthur Geddes; "rejected what was regarded as an overhasty plan for reconversion"; "wondered whether they had been rather precipitate in deposing the king"
Antonym: unhurried (indirect, via hurried)