impulsive

adjectives

proceeding from natural feeling or impulse without external stimulus
"an impulsive gesture of affection"
impulsive, unprompted
is derived from
impulsiveness
without forethought
"letting him borrow her car was an impulsive act that she immediately regretted"
impulsive
is derived from
impulsiveness
is similar to
not premeditated
unpremeditated
having the power of driving or impelling
"a driving personal ambition"; "the driving force was his innate enthusiasm"; "an impulsive force"
driving, impulsive
is derived from
impel
determined by chance or impulse or whim rather than by necessity or reason
"a capricious refusal"; "authoritarian rulers are frequently capricious"; "the victim of whimsical persecutions"
capricious, impulsive, whimsical
is derived from
impulsiveness
characterized by undue haste and lack of thought or deliberation
"a hotheaded decision"; "liable to such impulsive acts as hugging strangers"; "an impetuous display of spending and gambling"; "madcap escapades"; (`brainish' is archaic)
brainish, hotheaded, impetuous, impulsive, madcap, tearaway
is derived from
impulsiveness