Definition of sun:
(n) :
the star which the
Earth revolves around and receives light and warmth from.
[The Illustrated Oxford Dictionary, Oxford University Press, 1998]; a
star,
especially when seen as the centre of any single
solar system
(v) :
to expose to the warmth and radiation of the sun.; to warm or dry in the sunshine.
"beautiful bodies lying on the beach, sunning their bronzed limbs."