noun
Used in sports and competitions for starting before the signal; also used figuratively for premature actions.
彼は不正スタートで失格になった。
He was disqualified for a false start.
フライング is a more casual, abbreviated term for a false start, often used in everyday conversation.
Compound of 不正 (ふせい, 'unjust, improper') and スタート ('start'), a straightforward wasei-eigo construction.