1. wildly impulsive, reckless, or zany

1. a wildly impulsive or reckless person

Examples

• The madcap adventure took them across three countries in one weekend.
• Her madcap scheme to surprise her friend involved elaborate costumes and props.
• The comedy featured madcap chase scenes through the city.
• He was known as the office madcap, always pulling pranks on his coworkers.
• The madcap of the group suggested they go skydiving on a whim.
• Their madcap road trip was full of unexpected detours and mishaps.