Lengthen

[lengk-thuh n, leng-, len-] /ˈlɛŋk θən, ˈlɛŋ-, ˈlɛn-/

verb (used with object)
1.
to make ; make greater in .
verb (used without object)
2.
to become greater in ; grow or .
/ˈlɛŋkθən; ˈlɛŋθən/
verb
1.
to make or become longer
v.

late 14c., from length + -en (1). Related: Lengthened; lengthening. Earlier verb was simply length (c.1300).

Read Also:

Lengthier
[lengk-thee, leng-, len-] /ˈlɛŋk θi, ˈlɛŋ-, ˈlɛn-/ adjective, lengthier, lengthiest. 1. having or being of great ; very long: a lengthy journey. 2. tediously verbose; very long; too long: a lengthy speech. /ˈlɛŋkθɪ; ˈlɛŋθɪ/ adjective lengthier, lengthiest 1. of relatively great or tiresome extent or duration adj. 1759, American English, from length + -y (2). […]
Lengthily
[lengk-thee, leng-, len-] /ˈlɛŋk θi, ˈlɛŋ-, ˈlɛn-/ adjective, lengthier, lengthiest. 1. having or being of great ; very long: a lengthy journey. 2. tediously verbose; very long; too long: a lengthy speech. /ˈlɛŋkθɪ; ˈlɛŋθɪ/ adjective lengthier, lengthiest 1. of relatively great or tiresome extent or duration adj. 1759, American English, from length + -y (2). […]
Lengthman
/ˈlɛŋkθmən; ˈlɛŋθ-/ noun (pl) -men 1. a person whose job it is to maintain a particular length of road or railway line

Length-over-all
noun 1. Nautical. the entire length of a vessel, measured from the foremost point of the bow to the aftermost point of the stern.
Lengthways
[lengkth-weyz, length-, lenth-] /ˈlɛŋkθˌweɪz, ˈlɛŋθ-, ˈlɛnθ-/ adverb, adjective 1. . /ˈlɛŋkθˌweɪz; ˈlɛŋθ-/ adverb, adjective 1. in, according to, or along the direction of length 1590s, from length + -way, with adverbial genitive -s.