Search Result for "midnight sun":
Wordnet 3.0

NOUN (1)

1. the sun visible at midnight (inside the Arctic or Antarctic Circles);


The Collaborative International Dictionary of English v.0.48:

Midnight sun \Mid"night` sun\ The sun shining at midnight in the arctic or antarctic summer. [Webster 1913 Suppl.]
WordNet (r) 3.0 (2006):

midnight sun n 1: the sun visible at midnight (inside the Arctic or Antarctic Circles)