expression, godan verb (-ru)
look daggers at someone; glare angrily
Describes a fierce, angry glare, often with eyes narrowed into a sharp shape. The expression is typically used when someone is furious or scolding. Related to 目を三角にする (to glare).
See also: 目を三角にする
彼は怒って目が三角になった。
He got so angry that his eyes turned into triangles.
母は
My mother scolded me with a fierce glare.