Lengthen \Length"en\ (-'n), v. t. [imp. & p. p. Lengthened (-'nd); p. pr. & vb. n. Lengthening (-'n*[i^]ng).]

To extent in length; to make longer in extent or duration; as, to lengthen a line or a road; to lengthen life; -- sometimes followed by out.

What if I please to lengthen out his date. --Dryden.

Source: Webster's Revised Unabridged Dictionary (1913)