apple of the eye

/ˈæp.əl.əv.ðiˈaɪ/

ÆP · əl · əv · ÐIAꞮ (4 syllables)

English Noun

Definition

The pupil, or pupil and iris, of the eye, originally believed to be spherical; also, the eyeball.

Etymology

From Middle English appel of the eyȝe, appel of þe ye, perhaps dissimilated from Middle English ij appel (literally “eye-apple”). More at eye-apple.