The Collaborative International Dictionary of English v.0.48:

Sunburning \Sun"burn`ing\, n.
   Sunburn; tan. --Boyle.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sunburn \Sun"burn`\, v. t. [imp. & p. p. Sunburnedor
   Sunburnt; p. pr. & vb. n. Sunburning.]
   To burn or discolor by the sun; to tan.
   [1913 Webster]

         Sunburnt and swarthy though she be.      --Dryden.
   [1913 Webster]