unsportsmanlike
Not behaving fairly or respectfully during a game or competition.
Unsportsmanlike describes behavior that violates the spirit of fair play and respect in sports or competition. When a player shoves an opponent after losing a point, complains constantly about the referee's calls, or celebrates a victory by mocking the other team, they're being unsportsmanlike.
The word comes from the ideal of sportsmanship: the idea that how you compete matters as much as whether you win. Good sportsmanship means playing by the rules, respecting your opponents, and accepting outcomes gracefully. Unsportsmanlike conduct is the opposite. It includes actions like intentionally trying to injure another player, pretending to be fouled when you weren't, or throwing a tantrum when things don't go your way.
In organized sports, referees can penalize unsportsmanlike behavior with penalties, yellow cards, or even ejection from the game. A soccer player who curses at the referee might receive a yellow card for unsportsmanlike conduct. A basketball player who deliberately trips an opponent is being unsportsmanlike.
The word also applies beyond sports. Someone who gloats excessively after winning a spelling bee or refuses to shake hands after losing a chess match is acting unsportsmanlike. The concept reminds us that competition should bring out our best qualities: determination, skill, and grace under pressure, not pettiness, anger, or disrespect.