lag

UK: /ˈlæg/ US: /læg/ ,(lag)

Inflections of 'lag' (v): (⇒ conjugate)

lags

v 3rd person singular

lagging

v pres p

lagged

v past

lagged

v past p

WordReference Random House Learner's Dictionary of American English © 2025

lag¹ /læg/   v., lagged, lag•ging, n. 
v. 

1. to fail to keep up or maintain a desired pace or speed: [no object]
   to lag behind in production.
   [~ + object]
   The construction industry still lags the economy.
2. to decrease gradually:
   [no object] Interest lagged as the meeting dragged on.

n. [countable]

3. a lagging behind:
   a lag in production.
4. a period of time in which there is a delay or slowing down:
   a lag of ten minutes.

WordReference Random House Unabridged Dictionary of American English © 2025

lag¹  (lag), v., lagged, lag•ging, n. 
v.i. 

1. to fail to maintain a desired pace or to keep up;
   fall or stay behind:
   After five minutes of hard running, some of them began to lag.
2. to move or develop slowly, as toward a goal or objective, or in relation to an associated factor (often fol. by behind):
   to lag behind in production.
3. to delay or fail in reaching full development:
   The factory lags regularly in making its quota.
4. to hang back;
   linger;
   delay:
   The old friends lagged because they wanted to talk some more.
5. to decrease, wane, or flag gradually, as in intensity:
   Interest lagged as the meeting went on.
6. Games [Marbles.] to throw one's shooting marble toward a line (lag line) on the ground in order to decide on the order of play.
7. Games [Billiards, Pool.] string (def. 17b).

v.t. 

8. to fail to keep up with:
   The industry still lags the national economy.
9. [Obs.] to cause to lag.

n. 

10. a lagging or falling behind;
    retardation.
11. a person who lags behind, is the last to arrive, etc.
12. an interval or lapse of time:
    There was a developmental lag in the diffusion of ideas.
13. Mechanics the amount of retardation of some motion.
14. Electricity the retardation of one alternating quantity, as current, with respect to another related alternating quantity, as voltage, often expressed in degrees.
15. Games [Marbles, Billiards.] the act of lagging.

• Scandinavian: compare Norwegian lagga to go slowly
• 1505–15

Synonyms

• 1. loiter, linger.
• 10. slowing, slowdown.

Antonyms

• 1. hasten.

lag²  (lag), v., lagged, lag•ging, n. [Chiefly Brit. Slang.]
v.t. 

1. British Terms to send to penal servitude;
   imprison.

n. 

2. British Terms a convict or ex-convict.
3. a period or term of penal servitude;
   prison sentence.

• origin, originally uncertain 1565–75

lag³  (lag), n., v., lagged, lag•ging. 
n. 

1. Building one of the staves or strips that form the periphery of a wooden drum, the casing of a steam cylinder, or the like.
2. Building [Masonry.] a crosspiece between ribs in a centering.

v.t. 

3. Mechanical Engineering, Building to line or cover (an excavation) with lagging.
4. Building to cover with insulation, as a steam boiler, to prevent radiation of heat.

• Scandinavian; compare Swedish lagg stave
• 1665–75

Collins Concise English Dictionary © HarperCollins Publishers::

lag / læɡ/ verb (lags, lagging, lagged)(intransitive)

1. (often followed by behind) to hang (back) or fall (behind) in movement, progress, development, etc
2. to fall away in strength or intensity

noun

1. the act or state of slowing down or falling behind
2. the interval of time between two events, esp between an action and its effect

Etymology: 16th Century: of obscure origin

lag / læɡ/ noun

1. a convict or ex-convict (esp in the phrase old lag)
2. a term of imprisonment

verb (lags, lagging, lagged)

1. (transitive) to arrest or put in prison

Etymology: 19th Century: of unknown origin

lag / læɡ/ verb (lags, lagging, lagged)

1. (transitive) to cover (a pipe, cylinder, etc) with lagging to prevent loss of heat

noun

1. the insulating casing of a steam cylinder, boiler, etc; lagging
2. a stave or lath

Etymology: 17th Century: of Scandinavian origin; related to Swedish lagg stave