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

This lash-lengthening Maybelline mascara and a pack of hydrating lip balm from Burt’s Bees, a brand Margot Robbie has worn. — Isabel Garcia, PEOPLE, 6 Sep. 2026

The new style is part of the Gucci Primavera collection, and the Donna features a striking, pronounced outline and clean lines all around, lengthening the leg. — Karla Rodriguez, Footwear News, 4 Sep. 2026

The piece was based on a recent study from UCLA that found that waiting times for surgery for nonmetastatic breast, colon, lung, pancreatic, gastric and esophageal cancer have lengthened across the board over the last 10 years or so. — Business Columnist, Los Angeles Times, 3 Sep. 2026

These Spanx Micro Flare Pants have a subtle bootcut design for an ultra-flattering, leg-lengthening look. — Melony Forcier, Travel + Leisure, 2 Sep. 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