(pathology) collagenosis, collagen disease

(fiction) Hanahaki, an illness affecting those consumed by unrequited love that manifests as the coughing up of flowers, which clears up upon reciprocation. A fictional illness, it has found popularity among both Japanese and foreign online fanfic (especially) artists and authors for its poetic quality.

square moated burial (ancient Japanese grave)

braces (device for straightening teeth)

an incisivus labii superioris muscle

(relativity) the theory of relativity

(rare) duality

influenza

corrosion resistance

(medicine) venereal disease (VD), sexually transmitted disease (STD)