impulsive
1. [ adjective ] determined by chance or impulse or whim rather than by necessity or reason
Synonyms: whimsical capricious
Examples:

"a capricious refusal" "authoritarian rulers are frequently capricious" "the victim of whimsical persecutions"

Related terms: arbitrary
2. [ adjective ] having the power of driving or impelling
Synonyms: driving
Examples:

"a driving personal ambition" "the driving force was his innate enthusiasm" "an impulsive force"

Related terms: dynamic
3. [ adjective ] without forethought
Examples:

"letting him borrow her car was an impulsive act that she immediately regretted"

Related terms: unpremeditated
4. [ adjective ] proceeding from natural feeling or impulse without external stimulus
Synonyms: unprompted
Examples:

"an impulsive gesture of affection"

Related terms: spontaneous
5. [ adjective ] characterized by undue haste and lack of thought or deliberation
Synonyms: impetuous tearaway madcap brainish hotheaded
Examples:

"a hotheaded decision" "liable to such impulsive acts as hugging strangers" "an impetuous display of spending and gambling" "madcap escapades" (`brainish' is archaic)

Related terms: archaism incautious
Similar spelling:   impulsively
  impulse
  impulsion
  impulse-buy