noun
corner of the eye
Refers specifically to the outer or inner corner of the eye. Often used in expressions like 眦を決する (to glare at someone with determination) or 眦が裂ける (to have one's eyes wide open in anger).
彼は眦を決して相手をにらんだ。
He glared at his opponent with fierce determination.
怒りで眦が裂けそうだった。
His eyes seemed to split at the corners from anger.
目尻 is the more common word for the outer corner of the eye, while 眦 is more literary and often used in idiomatic expressions.
The kanji 眦 is composed of 目 (eye) and 此 (this/here), but the exact historical derivation is uncertain. The reading まなじり is a native Japanese word.