What does lag mean?
“Lag” describes both a delay and the act of failing to keep pace. As a noun, it can refer to an interval between two related events, such as a time lag between a policy change and its measurable effect, or to a general period of falling behind. As a verb, it commonly takes “behind”: a region may lag behind in economic growth, a response may lag behind demand, or a runner may lag behind the leaders. The word is useful because it captures not merely lateness but a persistent gap between progress and what is expected. It is especially common in formal reporting about business, economics, technology, administration, and public responses, though its basic sense is entirely general.
A delay or period of time between one event and another; an instance of falling behind.
"The economy continued to experience a lag in its recovery."
Often used with “in,” “between,” or “of,” as in “a lag in progress” or “a lag of several months.”
To move, develop, or respond more slowly than expected or than another person or thing.
"Demand continued to lag behind supply last quarter."
Frequently used with “behind,” as in “lag behind competitors.”
The plural is used for separate delays or periods of falling behind, and is less common than the singular abstract use.
"The report identified persistent lags in the processing of applications."
A lag is the space between progress and expectation: the time before a change catches up.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does lag come from?
The word appears in English by the late 16th century in senses associated with delay and falling behind. Its deeper origin is not securely established, and historical accounts differ on whether the modern verb developed from the noun or from related earlier forms. The expression “lag behind” became especially established during the 18th and 19th centuries for describing delay or inferior position.
Related word forms
How lag is actually used
The noun and verb are standard in British and American English. “Lag” is often used in business, economics, technology, and discussion of delayed responses. “Time lag” is especially common, while “lag behind” is a frequent verbal construction.
Easily confused with lag
A latch is a fastening or mechanism that closes a door or gate, whereas a lag is a delay or an instance of falling behind.
Lack means an absence or insufficiency of something, while lag means a delay or a failure to keep pace.