Synonyms of the word

brainish

• adj. (obsolete) hot-headed; furious.

hotheaded

• adj. Pertaining to or characteristic of a hothead or hotheadedness; (of a person) easily excited or angered.

impetuous

• adj. Making arbitrary decisions, especially in an impulsive and forceful manner.
• adj. Characterized by sudden violence or vehemence.

impulsive

• adj. Having the power of driving or impelling; giving an impulse; moving; impellent.
• adj. Actuated by impulse or by transient feelings; inclined to make rapid decisions without due consideration.
• adj. (mechanics) Acting momentarily, or by impulse; not continuous – said of forces.
• n. That which impels or gives an impulse; an impelling agent.
• n. One whose behaviour or personality is characterized by being impulsive.

incautious

• adj. careless, reckless, not exercising proper caution.

madcap

• adj. impulsive, hasty or reckless; capricious.
• n. An impulsive, hasty, capricious person.
• n. (obsolete) An insane person, a lunatic.

tearaway

• n. (informal, chiefly Britain, pejorative) An impetuous and reckless person who is difficult to control;…