LENGTH'EN, v.t. length'n.

1. To extend in length; to make longer; to elongate; as, to lengthen a line.

2. To draw out or extend in time; to protract; to continue in duration; as, to lengthen life. The days lengthen from December to June.

3. To extend; as, to lengthen a discourse or a dissertation.

4. To draw out in pronunciation; as, to lengthen a sound or a syllable. This verb is often followed by out, which may be sometimes emphatical, but in general is useless.

What if I please to lengthen out his date?

LENGTH'EN, v.i. To grow longer; to extend in length. A hempen rope contracts when wet, and lengthens when dry.