名詞 madcap:

1. a reckless impetuous irresponsible person
   同義詞：daredevil, hothead, swashbuckler, lunatic, harum-scarum

形容詞 madcap:

1. characterized by undue haste and lack of thought or deliberation; (`brainish' is archaic)
   同義詞：hotheaded, impulsive, impetuous, tearaway, brainish

mad.cap

adj.（形容詞）
Behaving or acting impulsively or rashly; wild.
魯莽的：舉止行為沖動的或魯莽的；狂亂的

來源：
mad
mad
cap [head]
cap[頭]

【引伸】
mad.cap.
n.（名詞）