The Collaborative International Dictionary of English v.0.48:
Windless \Wind"less\, a. 1. Having no wind; calm. [1913 Webster] 2. Wanting wind; out of breath. [1913 Webster] WindlestraeWordNet (r) 3.0 (2006):
windless adj 1: without or almost without wind; "he prefers windless days for playing golf"