lengthen

verb

length·​en ˈleŋ(k)-thən 

ˈlen(t)-

lengthened; lengthening

ˈleŋ(k)th-niŋ, 

ˈlen(t)th-;

  ˈleŋ(k)-thə- 

ˈlen(t)-

transitive verb

: to make longer

intransitive verb

: to grow longer

lengthener

ˈleŋ(k)th-nər, 

ˈlen(t)th-;

  ˈleŋ(k)-thə- 

ˈlen(t)-

noun

Synonyms of lengthen

• extend
• prolong
• increase
• stretch
• elongate

Choose the Right Synonym for lengthen

extend, lengthen, prolong, protract mean to draw out or add to so as to increase in length.

extend and lengthen imply a drawing out in space or time but extend may also imply increase in width, scope, area, or range.

extend a vacation

extend welfare services

lengthen a skirt

lengthen the workweek

prolong suggests chiefly increase in duration especially beyond usual limits.

prolonged illness

protract adds to prolong implications of needlessness, vexation, or indefiniteness.

protracted litigation

Examples of lengthen in a Sentence

The days lengthened with the approach of spring.

Proper care will lengthen the life of the engine.

lengthen a pair of trousers

Recent Examples on the Web

Restaurant operators acknowledged their own faults for lengthening the permit process, including by providing incorrect or incomplete information, according to the report. —Miguel Otárola, Denver Post, 5 Mar. 2026

That changed in the early 1970s, when Texans approved a constitutional amendment that lengthened the governor’s term from two years to four years, taking effect for the 1974 election cycle (governors elected in 1974 and after would serve four-year terms). —Dante Motley, Austin American Statesman, 3 Mar. 2026

The Ribcage Wide-Leg jeans have a high-rise waist that’s right on trend, along with a leg-lengthening inseam and non-stretch denim that breaks in beautifully. —Annie Blackman, InStyle, 3 Mar. 2026

Starting pitchers are lengthening starts, prospects are turning heads and the World Baseball Classic is about to start. —Ken Sugiura, AJC.com, 2 Mar. 2026

Word History

First Known Use

14th century, in the meaning defined at transitive sense

Rhymes for lengthen

• strengthen

Kids Definition

lengthen

verb

length·​en ˈleŋ(k)-thən 

ˈlen(t)-

lengthened; lengthening ˈleŋ(k)th-(ə-)niŋ 

ˈlen(t)th-

: to make or become longer

lengthener

ˈleŋ(k)th-(ə-)nər 

ˈlen(t)th-

noun