\Light"en\ (l[imac]t"'n), v. i. [See {Light} to alight.]
To descend; to light.
      O Lord, let thy mercy lighten upon us.   --Book of
                                               Common Prayer
                                               [Eng. Ed.].

\Light"en\ (l[imac]t"'n), v. i. [imp. & p. p.
{Lightened} (-'nd); p. pr. & vb. n. {Lightening}.] [OE.
lightenen. See {Light} to kindle, illuminate.]
1. To burst forth or dart, as lightning; to shine with, or
   like, lightning; to display a flash or flashes of
   lightning; to flash.
         This dreadful night, That thunders, lightens, opens
         graves, and roars As doth the lion.   --Shak.
2. To grow lighter; to become less dark or lowering; to
   brighten; to clear, as the sky.

\Light"en\, v. t. [See {Light} to illuminate.]
1. To make light or clear; to light; to illuminate; as, to
   lighten an apartment with lamps or gas; to lighten the
   streets. [In this sense less common than light.]
         A key of fire ran all along the shore, And lightened
         all the river with a blaze.           --Dryden.
2. To illuminate with knowledge; to enlighten. [In this sense
   less common than enlighten.]
         Lighten my spirit with one clear heavenly ray. --Sir
                                               J. Davies.
3. To emit or disclose in, or as in, lightning; to flash out,
   like lightning.
         His eye . . . lightens forth Controlling majesty.
                                               --Shak.
4. To free from trouble and fill with joy.
         They looked unto him, and were lightened. --Ps.
                                               xxxiv. 5.

\Light"en\, v. t. [See {Light} not heavy.]
1. To make lighter, or less heavy; to reduce in weight; to
   relieve of part of a load or burden; as, to lighten a ship
   by unloading; to lighten a load or burden.
2. To make less burdensome or afflictive; to alleviate; as,
   to lighten the cares of life or the burden of grief.
3. To cheer; to exhilarate.
         Lightens my humor with his merry jests. --Shak.