(simile) Very straight; travelling in a very straight trajectory. / (simile, by extension) Having no homosexual desires or thoughts; completely heterosexual.

(chiefly Britain) Very fit; in good shape.

(simile, of someone's appearance) Very fresh; well-rested.

(simile, UK, slang) Extremely dishonest or criminally-minded. / (simile, UK, slang) Ostentatiously homosexual.

(simile, of water) Very calm, not choppy.

(simile) Very visually attractive.

(simile, slang) Very stupid.

(simile) Very chirpy; full of energy; very energetic

Alternative form of happy as a clam

(simile, colloquial) surely; doubtlessly