sharp sidelong glance; glare
A hostile or suspicious look directed sideways, often with the head slightly turned. Conveys anger, distrust, or intimidation.
He gave me a sharp sidelong glare.
Noticing my boss's sidelong glare, I hurried back to work.
Standard kanji spelling using 睨 (glare).
Kana-mixed spelling, common when the kanji 睨 is considered difficult or for emphasis.
Compound of 横 (side) and 睨み (glare, from verb 睨む). The exact historical derivation is uncertain, but the meaning is transparent from its components.