The Collaborative International Dictionary of English v.0.48:
Duskiness \Dusk"i*ness\, n. The state of being dusky. [1913 Webster]WordNet (r) 3.0 (2006):
duskiness n 1: the state of being poorly illuminated [syn: dimness, duskiness] 2: a swarthy complexion [syn: darkness, duskiness, swarthiness]