What does ab mean?
"Ab" is the informal short form of "abdominal muscle," one of the muscles running along the front of the human torso. In practice the word is nearly always heard in its plural form, "abs" — as when people talk about working their abs, toned abs, or six-pack abs — because the muscles are discussed as a group rather than individually. The term belongs firmly to informal register: it dominates gyms, fitness magazines, sports commentary, and everyday chat about exercise, while medical or anatomical writing prefers the fuller terms "abdominal muscles" or specific muscle names such as the rectus abdominis. Its brevity is part of its appeal; it fits naturally into compound phrases like "ab workout." Though modest as vocabulary goes, it is a genuinely useful word for anyone discussing fitness in English, and its origin is easy to remember: it simply clips the first syllable of "abdominal," which itself derives from the Latin "abdomen," meaning belly.
nounAn informal shortening of 'abdominal muscle', referring to any of the muscles of the front of the torso; usually encountered in its plural form 'abs'.
- Informal short form of 'abdominal muscle', one of the muscles of the front of the trunk of the body.
"Planks and crunches are great for strengthening your abs."
"He does a hundred crunches every morning to keep his abs in shape."
"The workout focuses on the core, especially the lower abs."
This is by far the most common form of the word in actual use; the singular 'an ab' is rarely said.
"Swimming is excellent for building strong abs without straining your back."
Your 'abs' are literally named after your belly — 'ab' is just gym-floor shorthand for the Latin-derived 'abdominal'.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of ab
The word "ab" arose as a clipping — an informal shortening — of "abdominal," the adjective describing the muscles of the abdomen. "Abdominal" itself traces back through Middle French to the Latin "abdomen," the classical word for the belly. The clipped form became widespread in late twentieth-century fitness culture, particularly in North America, as shorthand for the abdominal muscles targeted by exercises like sit-ups and crunches.
Related word forms
How ab is actually used
Almost always used in the plural ('abs') in everyday speech; the singular 'an ab' is rare and sounds odd to most speakers. The word is informal and belongs chiefly to fitness, sports, and casual conversation.
Easily confused with ab
'Abb' is a word for yarn or a woof thread in weaving, whereas 'ab' is the informal term for an abdominal muscle.