adjective
steep, falling sharply
Synonyms: abrupt, arduous, craggy, dizzy, dizzying, high, perpendicular, precipitate, sharp, sheer
Antonyms: gradual
adjective
fast, sudden; impulsive; initial
Synonyms: abrupt, breakneck, brief, frantic, gone off half-cocked, harum-scarum, hasty, headlong, heedless, hurried, ill-advised, impatient, impetuous, indiscreet, jump the gun, madcap, off the hip, off the top of head, plunging, precipitant, quick, rapid, rash, reckless, refractory, rushing, subitaneous, swift, unanticipated, uncontrolled, unexpected, unforeseen, violent, willful, without warning
Antonyms: careful, cautious, slow