WordReference Random House Learner's Dictionary of American English © 2026
op•ti•cal /ˈɑptɪkəl/USA pronunciation
adj. [before a noun]
WordReference Random House Unabridged Dictionary of American English © 2026- Opticsof, relating to, or applying optics.
- Ophthalmologyof or relating to the eye or eyesight:an optical illusion (= something that is not really the way the eye perceives it).
op•ti•cal
(op′ti kəl),USA pronunciation adj.
n.
op′ti•cal•ly, adv.
- of, pertaining to, or applying optics or the principles of optics.
- constructed to assist sight or to correct defects in vision.
- of or pertaining to sight or vision;
visual. - of or pertaining to the eye.
- Ophthalmologyof or pertaining to an optician or opticians or to their products, esp. eyeglasses:an optical service.
- dealing with or skilled in optics.
n.
- Cinema opticals. See optical effects.
- optic + -al1 1560–70
'optically' also found in these entries (note: many are not synonyms or translations):
chirality
- glucose
- hyoscyamine
- image
- menthol
- optical character reader
- quinidine
- warfarin
- limonene
- mannitol
- maverick
- optical rotation
- pointillism
- racemic acid
- racemism
- racemization
- resolve
- wand
- synthetic