noun

1. the fact or condition of not having enough; shortage; deficiency
2. the fact or condition of not having any; complete absence
3. the thing that is lacking or needed

Etymology: early ME lac < or akin to MLowG & MDu lak, lack: for IE base see leak

intransitive verb

1. to be wanting or missing; show a deficiency
2. 1. to be short: with in, for, or, now rarely, of
   2. to be in need

Etymology: ME lacen < MDu laken, to be wanting

transitive verb

1. to be deficient in or entirely without
2. to fall short by lacking one ounce of being a pound
3. Obsolete to need; require