Length″en (–'n), v. t. [imp. & p. p.Lengthened (–'nd); p. pr. & vb. n.Lengthening (–'n‐ĭng).] 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.