Etymology Dictionary

LAG,   sluggish, coming behind.  (C.)   'Came too lag [late] to see him buried;' Rich. III, ii. 1. 90.   Cf. prov. E. lag, late, last, slow; lag-last, a loiterer; lag-teeth, the grinders, so called because the last in growth; Halliwell.—W. llag, slack, loose, sluggish. + Gael. and Irish lag, weak, feeble, faint. + Corn. lac, adv. loose, remiss, lax, out of order, bad (Williams). + Lat. laxus, lax, loose; cf. Lat. languor, languor; languidus, languid.   Cf. Icel. lakra, to lag behind.   β. The form of the root is LAG, to be slack or loose; whence also E. lax, languid; and Gk. λαγαρός, slack; see Languish.   Der. lag, verb, Spenser, F. Q. i. 1. 6, with which cf. Corn. lacca, to faint away, Gk. λήγειν, to cease; also lagg-ing-ly, lagg-er, lag-end, 1 Hen. IV, v. 1. 24; lagg-ard (a late word), where the suffix -ard is French (of Teut. origin) and is affixed even to English bases, as in drunk-ard. [†]

ADDENDA

We again find lag, late, in Jacob and Esau, v. 5, in Dodsley's O. Plays, ii. 252, where Esau is said 'of blessing to come lag.'   Hence the verbal use, as in:  'Death shall not long lag after him;' id. x. 48.