flutter

an abnormally rapid vibration or pulsation of one's heart, particularly in an irregular rhythm

the act of moving back and forth

the motion made by flapping up and down

a disorderly outburst or tumult

a casual or impulsive bet, often made on a whim or without much forethought

A flutter is a small, casual bet, often placed impulsively or without much planning. It is usually a lighthearted wager made for fun or excitement, rather than for serious financial gain. People might place a flutter on various events, such as horse races or sports games, without thoroughly analyzing the odds or outcomes. The term suggests an easygoing approach to gambling, where the amount of money bet is typically modest, and the focus is more on the thrill of the bet than on making a significant profit.