verb

• (intransitive) To incline, deviate, or bend, from a vertical position; to be in a position thus inclining or deviating.
  "a leaning column"
• (copulative) To incline in opinion or desire; to conform in conduct; often with to, toward, etc.
  "I’m leaning towards voting Conservative in the next election."
• (Followed by against, on, or upon) To rest or rely, for support, comfort, to use as a hard surface for writing, etc.
  "He lean'd not on his fathers but himself."

noun

• (of an object taller than its width and depth) An inclination away from the vertical.
  "The trees had various leans toward gaps in the canopy."

adj

• (of a person or animal) Slim; not fleshy.
  "They will now dedicate several hours at the gym every day to be leaner and stronger."
• (of meat) Having little fat.
  "lean steak cuts"
• (printing, archaic) Of a character which prevents the compositor from earning the usual wages; opposed to fat.
  "lean copy, matter, or type"
• (business) Efficient, economic, frugal, agile, slimmed-down; pertaining to the modern industrial principles of "lean manufacturing".
  "lean management"

noun

• (uncountable) Meat with no fat on it.
  "Jack Sprat would eat no fat, / His wife would eat no lean."
• (countable, biology) An organism that is lean in stature.
  "The intermediates and leans are the predominant morphotypes found at the SE-NHR seamounts […]"