Medicine & BodyGreek → English
Deltoid
/ˈdɛltɔɪd/noun
The triangular muscle capping the shoulder, which lifts the arm away from the body.
The Greek roots
δέλτα
délta
the letter delta
εἶδος
eîdos
form, shape
Literally: “delta shaped”
The story of the word
The muscle is a triangle with its point aimed down the arm, so anatomists named it after the shape of the capital letter. Herodotus had applied the same triangle to the mouth of the Nile in the fifth century BC, which is why every river fan on earth is now a delta. The letter itself goes back to Phoenician daleth, a door.
- How it travelled
- Ancient Greek → Latin → English
- First recorded
- 18th century
Same family
deltadeltiologyrhomboid
In a sentence
The nurse gave the injection into the deltoid and had him move the arm straight away.
Six months of swimming had visibly built up his deltoids.