Determiner

1. ;The smallest amount of [something uncountable].

   He earns the least money in his family.

   Of all the sisters, she has the least patience.

   I can only afford to pay the least of the bills.

   • 1857, Edmund March Blunt, The American Coast Pilot: Containing Directions for the Principal Harbors, E. & G.W. Blunt, page 135:

     The least water we could find there was 4 fathoms, which bears from the point S.E., and is distant 1½ mile.

   • 2004, Jim Baggott, Beyond Measure: Modern Physics, Philosophy, and the Meaning of Quantum Theory, Oxford University Press, page 48:

     Light does not need to know in advance which is the path of least time because it takes all paths from its source to its destination.

Usage notes

• 1965, H. W. Fowler, Fowler’s Modern English Usage: Second Edition:

  [W]hen the context—unemotional statement of everyday facts—is taken into account, at a less price ought to be at a lower price, and a lesser prize ought to be a smaller prize.

Adverb

1. Used for forming superlatives of adjectives, especially those that do not form the superlative by adding -est.

   It was the least surprising thing.