Is there a difference between the pair dexter/sinister (right/left) and rectus/laevus?

I was only aware of the pair dexter/sinister until recently, when I learned that chiral molecules in molecular biology are labeled "D" and "L" to signify right- and left-handed versions. These letters are apparently inspired by dexter and laevus, which is perhaps extra surprising since it seems like this combines one word each from two common pairings, rather than sticking to a single pairing (e.g., "D" and "S", or "R" and "L".)

  • 2
    There's yet a third word for left, scaevus.
    – TKR
    Nov 2, 2019 at 17:16

1 Answer 1


Dexter and rectus

"Dexter" is the term for "right" as in one's right hand. "Rectus" never means "right" in this sense; it means straight, upright, direct, or correct, but it doesn't mean right as the opposite of left.

Sinister, laevus, scaevus

"Sinister" has a much longer entry than the other two in the Oxford Latin Dictionary, and is described by Ernout & Meillet (Dictionnaire étymologique de la langue latine) as "the usual term" for "left".

"Laevus" is regarded by Lewis & Short as "mostly poetic".

"Scaevus" is described by Ernout & Meillet as "used above all in augural language or in figurative senses". E & M note that "the names for 'left' are various (by contrast with those for 'right')".

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.