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

In a shocking reversal in strategy, Universal Pictures is lengthening the time that its movies will play exclusively in theaters. —Rebecca Rubin, Variety, 12 Mar. 2026

The season has lengthened by 19 days on average in the southeast specifically, creating a 136 day window where there are no freezes and plants are able to grow and pollinate. —Irene Wright, USA Today, 12 Mar. 2026

This time around, Verlander can slot in between RHPs Jack Flaherty and Casey Mize in lengthening out one of the game’s best rotations. —Jeff Sanders, San Diego Union-Tribune, 11 Mar. 2026

The semi-sheer knit crochet top layers seamlessly over a tank for depth and contrast without losing coziness, while the gently high-rise, wide-leg pants add a leg-lengthening effect that makes the whole look feel polished and on-trend. —Annie Blackman, InStyle, 11 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