1. (

• hotheaded ,
• impulsive ,
• impetuous ,
• madcap ,
• tearaway ,
• brainish

) 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) ;