Wanting flesh; destitute of or deficient in fat; slim; not plump; slender; meager; thin; lank; as, a lean body; a lean cattle.

Wanting fullness, richness, sufficiency, or productiveness; deficient in quality or contents; slender; scant; barren; bare; mean; -- used literally and figuratively; as, the lean harvest; a lean purse; a lean discourse; lean wages.

Of a character which prevents the compositor from earning the usual wages; -- opposed to fat; as, lean copy, matter, or type.

That part of flesh which consists principally of muscle without the fat.

To incline, deviate, or bend, from a vertical position; to be in a position thus inclining or deviating; as, she leaned out at the window; a leaning column.

To incline in opinion or desire; to conform in conduct; -- with to, toward, etc.

To cause to lean; to incline; to support or rest.

the property possessed by a line or surface that departs from the vertical; "the tower had a pronounced tilt"; "the ship developed a list to starboard"; "he walked with a heavy inclination to the right"

Refers to carburetor setting. When an engine is run too lean it will overheat, causing damage, and likely an in flight engine failure. Tuning a carburetor is best accomplished by starting rich, and working gradually to the condition which produces maximum power, while allowing a small amount of unburned fuel mixture to lubricate and cool the engine.

carburetor setting are called lean when the mixture of fuel and air are biased toward more air than would be used in the standard mixture.

A condition where the air-fuel mixture is not the correct ratio (not enough fuel relative to the amount of air). High HC and/or high NOx emissions are symptoms of a lean air fuel ratio.

When the air - fuel mixture is too rich, the driver may adjust the needles to lean out the mixture, i.e. increase the air to fuel ratio. If the engine runs too lean, it may get too hot which can severly damage the engine. The piston may get stuck inside of the cylinder.

Refers to the directional tilt of a tree away from its vertical position. Many times two lean forces may be in play in the same tree. They are referred to as head lean and side lean.

A hunter’s blind built in or at the base of a tree.

cause to lean to the side; "Erosion listed the old tree"

A tree trunk that is not vertical.