Glossary
Tennis terms explained in a paragraph: what they mean and what you are seeing when you hear them. Definitions, not instructions; the how and why lives in the articles.
A
Ace
A serve that lands in the service box and is not touched by the receiver, winning the point outright.
ATP 250
The entry level of the ATP Tour, worth 250 ranking points to the champion; 29 events in 2026, usually one week with a 28- or 32-player draw.
ATP 500
The middle tier of ATP Tour events, worth 500 ranking points to the champion; there are 16 in 2026 and the top 30 must play at least four.
ATP Race
The calendar-year points table, officially the PIF ATP Race To Turin, that decides which eight players qualify for the Nitto ATP Finals.
B
Bagel
Slang for a set won or lost 6-0, named for the shape of the zero; a double bagel is a 6-0, 6-0 match.
Break point
A point the returner can win to take the game from the server, at 30-40, 15-40, 0-40 or advantage to the receiver.
C
Career Grand Slam
Winning all four major singles titles at some point in a career, not necessarily in the same year; nine men and ten women have done it.
Challenger Tour
The second level of men's professional tennis, directly below the ATP Tour, where players earn the ranking points that get them into the top 100.
D
Deuce
The score at 40-40, when both players have won three points in a game; from there a player needs two points in a row to win the game.
Double fault
Two service faults in a row on the same point; the server loses the point without a rally.
G
Golden set
A set won without losing a single point, 24 in a row; it has happened once in a Grand Slam main draw, by Yaroslava Shvedova at Wimbledon in 2012.
Golden Slam
All four majors plus Olympic singles gold; in one calendar year only Steffi Graf has done it (1988), while five players hold the career version.
Grand Slam
One of the four majors (Australian Open, Roland-Garros, Wimbledon, US Open) or, strictly, the feat of winning all four in one calendar year.
H
Hawk-Eye
The camera-based ball-tracking system behind electronic line calling; since 2025 it has replaced line judges on the ATP Tour and at three of the four majors.
L
Let
A call that stops the point and has it replayed; most often a serve that touches the net and still lands in the service box.
Love
Tennis's word for zero; a score of love means no points in the game, and a love set is one won 6-0.
Lucky loser
A player beaten in the final round of qualifying who gets into the main draw anyway when someone withdraws before their first match.
M
Masters 1000
The nine biggest ATP Tour events below the Grand Slams, worth 1,000 ranking points to the winner; seven now run for 12 days with 96-player draws.
Match tiebreak
A ten-point tiebreak that decides a match; all four Grand Slams play it at 6-6 in the final set, and in doubles it often replaces the third set.
Medical timeout
A three-minute break for on-court treatment by the physiotherapist, allowed once per distinct medical condition and never for cramping alone.
N
Night session
A separately ticketed evening programme on a tournament's main court; the US Open's starts at 7 p.m. with two matches and has produced finishes after 2 a.m.
P
Protected ranking
A frozen ranking that lets a player back from at least six months out through injury enter tournaments as if they had never stopped; not valid for seeding.
Q
Qualifier
A player who earned a main-draw place by winning through the qualifying tournament held in the days before the main event.
R
Retirement
When a player stops a match that has already started, usually through injury, and the opponent is awarded the win with the score as it stood.
S
Seeding
Ranking the strongest entrants and placing them in the draw so they cannot meet before the later rounds; the majors seed 32 players in singles.
T
Tiebreak
The game played at 6-6 in a set to decide it; the first player to seven points with a two-point margin wins the set 7-6.