(nautical) Length of a ship from bow to stern.

(physics) A unit of length, believed to be the smallest length that has physical meaning, that is defined in terms of the speed of light, the gravitational constant and the reduced Planck's constant, namely: ℓ_P=√hbar Gc³≈1.616 252(81)⨯10⁻³⁵ mbox meters

plural of cable length

The number of multiplicands needed, at a minimum, to express a given group element as a product of commutators.

plural of commutator length

(physics) A particular length or distance whose value is determined to one order of magnitude (or to very few orders of magnitude)

(literally) Barely within reach. / (idiomatic) Distant, detached. / (idiomatic) Independent, but related.

A distance approximately equal to the length of a human's arm. / (figuratively) A position not suggesting or inviting intimacy.

(cricket) The direction (line) and point at which a delivery hits the pitch (length) of a delivery considered as a whole, especially that of a group of a particular bowler's deliveries.

(optics) A measure of how strongly an optical system converges or diverges light, the inverse of optical power. In the simple case of a single convex lens, it is the distance along the optical axis from the principal plane of the lens to the lens's focal point (where, for instance, the film would be placed in a camera). For more complex or multi-element optical systems, focal length need not correspond to any obvious measurable physical distance.