A reminder that we are all mortal, as a justification for enjoying life while one can.

(marketing, software, testing) The use of a randomized experiment with two variants (termed A and B) which differ in a single particular.

(slang) To prepare to fight; to square up.

(Australia, slang) Perform a U-turn.

The universal chlorophyll (C₅₅H₇₂MgN₄O₅) essential to the dominant oxygenic photosynthesis I process, present in all eukaryotes, cyanobacteria, chromists, and prochlorophytes that photosynthesize, and that contributes to the observed green color of these organisms.

(idiomatic, chiefly in the negative) To sleep at all.

Asked to call upon a doctor to come forth from a group of people.

A person unaccustomed to wealth or luxury will easily be corrupted by it.

I am a doctor (a physician, a member of the medical profession)

(simile) To live in luxury, in costly and comfortable surroundings.