hypothetical enemy

(Internet slang, derogatory) Twittard

castella, a type of sponge cake

an inferior oblique muscle

an incisivus labii inferioris muscle

die-casting

Short for カスタマーハラスメント (kasutamā harasumento).

(ethnic slur, derogatory, Internet slang) Britain, British person

hackathon

(typography) a em-square or em-box, sometimes literally translated as "imaginary body" or "virtual body", whose dimension is 1em, that defines the bounds of a CJK glyph, or that is used for defining font size