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

One question contended that the number of scripts entering production are decreasing, investment is becoming cautious, and distribution cycles are lengthening. —Marcus Lim, Variety, 5 Dec. 2025

Thanks to a lengthening injury report (particularly to two-time All-Star point guard Jrue Holiday, who's been out for the last seven contests), the Trail Blazers have won just two of their last 10 games, and are currently in the midst of a three-game skid. —Alex Kirschenbaum, MSNBC Newsweek, 3 Dec. 2025

Choose from petite, regular, or tall inseams for a leg-lengthening fit that hits right at the ankle. —Gabriela Garcia, Travel + Leisure, 28 Nov. 2025

Tech giants have lengthened server lifespans on the books to six years. —Yun Li, CNBC, 25 Nov. 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