(algebra) binary operation

two-dimensional array

(chemistry) silicon dioxide

Alternative spelling of 中二病

(Internet slang) a “sickness” in teenagers characterized by sophomoric, edgy, and/or pretentious behavior (trying too hard to be special in unusual ways)

characterized by such behavior

double standard

double sole / double bottom

(swords) an inscription of two characters

a kind of comedy performance, wherein one person wears a 羽織 (haori) with their arms not in the sleeves and their head and face free and visible as normal, and another person behind slips into the same haori and puts their arms through the sleeves with the back of the haori over their own head, and then, without being able to see, tries to feed the first person