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

These pants sit high on the waist, creating a leg-lengthening effect, and the side slits at the hem are perfect for showing off your Cushionaire sandals. —Caroline Hughes, Travel + Leisure, 5 June 2026

And men are indeed lengthening their limbs, flying to international clinics, having metal rods inserted into their bones, and then, after a brutal recovery process, relearning how to walk. —Brady Brickner-Wood, New Yorker, 4 June 2026

Democratic leaders seem determined not to allow anything to get in the way of winning Maine’s Senate seat, even if that requires willful blindness toward Platner’s lengthening record of indiscretions. —Shannon A. Mullen, The Atlantic, 4 June 2026

Although the list of edible foods that double as fish bait could be lengthened, there are as many natural baits little known or used by the average fisherman. —Byron W. Dalrymple, Outdoor Life, 4 June 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