Glossary

Plain-language definitions of the terms you'll hear in boxing, MMA and kickboxing.

How fights end

KO (Knockout)KO（ノックアウト）: A fighter is knocked down and cannot continue (or is unconscious). An instant, definitive finish.
TKO (Technical Knockout)TKO（テクニカルKO）: The referee, corner or doctor stops the fight because one fighter can no longer safely defend themselves, even if not unconscious.
Submissionサブミッション（一本）: An MMA/grappling finish where a fighter forces the opponent to 'tap out' with a choke or joint lock.
Decision判定: If a fight goes the distance, judges' scorecards decide the winner. See unanimous / split / majority.
UD (Unanimous Decision)UD（全会一致判定）: All three judges scored the same fighter as the winner.
SD (Split Decision)SD（スプリット判定）: Two judges favored one fighter, the third favored the other — a close, contested result.
MD (Majority Decision)MD（マジョリティ判定）: Two judges scored for one fighter while the third scored it a draw.
Draw引き分け: The scorecards are level — no winner. A 'majority draw' or 'split draw' describes how the judges differed.
No Contest (NC)無効試合（NC）: A result is voided — often due to an accidental foul or a failed drug test. It doesn't count as a win or loss.
RTD (Retired)RTD（棄権）: A fighter's corner pulls them out between rounds (the fighter doesn't answer the bell).

W-L-D (e.g. 27-0-0)W-L-D（例：27-0-0）: A pro record: wins–losses–draws. 27-0-0 means 27 wins, no losses, no draws.
Finish rate / KO rateフィニッシュ率／KO率: The share of wins that came by knockout or submission, rather than by going to the judges.
Undefeated無敗: A fighter who has never lost a professional bout.

Undisputed championアンディスピューテッド（統一）王者: In boxing, the holder of all four major belts (WBA, WBC, IBF, WBO) in one weight class at once.
Unified champion統一王者（複数団体）: A champion holding two or more of the major belts (but not all four).
Interim title暫定王座: A 'stand-in' belt created when the real champion is inactive (injured, etc.). The interim champ usually fights the real champ next.
Pound-for-pound (P4P)パウンド・フォー・パウンド（P4P）: A mythical ranking of who is the best fighter regardless of weight class — 'if everyone were the same size.'
Mandatory challenger指名挑戦者: A top contender a sanctioning body requires the champion to fight within a set time.

Main eventメインイベント: The headline, last and most important fight of the night.
Co-main eventセミファイナル（共同メイン）: The second-biggest fight, on right before the main event.
Undercard / prelimsアンダーカード／プレリム: The fights before the main and co-main — often where prospects are built.
Weigh-in計量（ウェイイン）: The official weight check the day before. Missing weight can cost a fighter a title or a percentage of their purse.
Catchweightキャッチウェイト: A bout at an agreed weight that isn't a standard division limit.

Takedownテイクダウン: Bringing the fight to the ground by tackling, tripping or throwing the opponent.
Ground and poundグラウンド＆パウンド: Striking an opponent while controlling them on the mat.
Guardガード: Controlling an opponent from your back using your legs — a defensive but dangerous position in grappling.
Rear-naked choke (RNC)リアネイキッドチョーク（裸絞め）: A choke applied from an opponent's back — one of the most common submission finishes.
Armbarアームバー（腕ひしぎ）: A joint lock that hyperextends the elbow to force a tap.
Sprawlスプロール: A defensive move where a fighter throws their legs back to stop a takedown.

Orthodoxオーソドックス: A right-handed stance: left foot and hand forward.
Southpawサウスポー: A left-handed stance: right foot and hand forward. Tricky for orthodox fighters.
Jabジャブ: The lead-hand straight punch — used to measure distance, score and set up bigger shots.
Counterカウンター: A punch or kick thrown the instant the opponent attacks, using their momentum against them.
Low kick / leg kickローキック: A kick to the thigh or calf — a staple of kickboxing and Muay Thai that wears down an opponent's mobility.
Clinchクリンチ（組み）: Close-range grappling while standing — used to control, throw knees, or rest.
Checking a kickカット（蹴りのチェック）: Blocking a low kick with the shin so the attacker's leg takes the damage.