What does delt mean?
'Delt' is an informal abbreviation of 'deltoid', the name given to the thick, triangular muscle that caps the human shoulder. The name comes from the Greek letter delta (Δ), whose shape the muscle resembles. In everyday use, 'delt' appears almost exclusively in fitness and bodybuilding circles, where enthusiasts routinely break the muscle into regions — front delts, side (lateral) delts, and rear delts — when discussing exercises such as overhead presses, lateral raises, and reverse flyes. Because it belongs to gym slang rather than formal vocabulary, you will encounter it in workout plans, coaching cues, and athletic conversation far more often than in medical texts, where the full terms 'deltoid' or 'deltoideus' are standard. Its plural, 'delts', is as common as the singular, since training usually targets both shoulders at once. Compact and vivid, 'delt' is useful shorthand for anyone talking seriously about upper-body strength and physique development.
nounAn informal short form of 'deltoid', referring to the thick triangular muscle covering the shoulder joint, responsible for raising the arm. It is used chiefly in fitness, bodybuilding, and athletic contexts.
- Informal short form of deltoid: the large triangular muscle covering the shoulder, which lifts and rotates the arm.
"He built impressively broad delts with years of overhead pressing."
"Her rear delts were noticeably underdeveloped compared to the rest of her shoulders."
"The coach had him add lateral raises specifically to widen his side delts."
The plural is very common in gym contexts, since training typically addresses the muscles of both shoulders together.
"Lateral raises are the go-to exercise for building wider delts."
Bodybuilders talk about their 'delts' more than their shoulders — because this triangular muscle is named after the Greek letter delta, which looks exactly like the triangle it forms.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of delt
'Delt' arose in twentieth-century English as a simple clipping of 'deltoid', itself borrowed in the eighteenth century from modern Latin 'deltoideus'. That Latin term derives ultimately from the Greek 'deltos' (δέλτος), meaning the letter delta and, by extension, anything shaped like its triangle — including the Nile Delta. Words sharing this Greek root include 'delta' itself, the adjective 'deltic', and 'Deltaic' describing river deltas.
How delt is actually used
Strictly informal and jargon-like: common in gyms, bodybuilding magazines, and casual speech among athletes, but rare in formal anatomy writing, where 'deltoid' or 'deltoideus' is preferred.
Easily confused with delt
'Dealt' is the past tense of the verb 'deal' (to distribute or handle), whereas 'delt' is an informal noun for the shoulder's deltoid muscle.
'Deltoid' is the full anatomical term for the muscle; 'delt' is merely its casual gym-floor abbreviation.