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

• 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

Since official records began in 1973, Earth's solar day has been steadily lengthening, mostly due to the moon. —Jamie Carter, Space.com, 5 Aug. 2025

Perhaps his confidence in continuing the war is one more item on a lengthening list of his strategic mistakes. —Ian Bremmer, Time, 31 July 2025

The longer practice also lengthened the Chiefs’ injury list. —Blair Kerkhoff, Kansas City Star, 29 July 2025

Chewing raw plants and sinewy meats both strengthened and lengthened the jaw. —Burkhard Bilger, New Yorker, 28 July 2025

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