canthus

Borrowed from Latin canthus (“the tire of a wheel”).

• IPA^(key): /ˈkænθəs/

canthus (plural canthi)

1. (anatomy) Either corner of the eye, where the eyelids meet.
   • 1955, Vladimir Nabokov, Lolita:

     the lowly East with its deer head (dark trace of long tear at inner canthus

   • 2015 August 26, “Effects of Relaxing Music on Mental Fatigue Induced by a Continuous Performance Task: Behavioral and ERPs Evidence”, in PLOS ONE‎, DOI:10.1371/journal.pone.0136446:

     A ground electrode located between Fpz and Fz. The electro-oculogram (EOG) was recorded bipolarly from two electrodes placed at the outer canthi of the right eye and below the left eye.

• chaunts, staunch

Alternative spelling of cantus. The term for "rim of a wheel" is ultimately of Gaulish origin, from Proto-Celtic *kantos (“corner, rim”). Related to Breton kant (“circle”), Old Irish cétad (“round seat”), Welsh cant (“rim, edge”).

The frequent spelling with -th- is due to the influence of unrelated (or possibe Indo-European cognate) κανθός (kanthós) "corner of the eye", which after its borrowing became conflated with the Gaulish term for "rim" in Latin.[1]

canthus m (genitive canthī); second declension

1. the iron ring around a carriage wheel; the tire[2]
2. a wheel
3. (anatomy) corner of the eye

Second declension.