Synonyms for Madcap (same or very similar meaning)
WordNet sense 1 (a reckless impetuous irresponsible person):
daredevil, harum-scarum, hothead, lunatic, swashbuckler
WordNet sense 2 (characterized by undue haste and lack of thought or deliberation):
hotheaded, impetuous, impulsive, brainish, tearaway
WordNet sense 3 (lacking in caution):
incautious
From the ODE community, based on WordNet
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