Wordnet 3.0
NOUN (1)
1.
a mass of snow heaped up by the wind;
The Collaborative International Dictionary of English v.0.48:
Snowdrift \Snow"drift`\, n.
A bank of drifted snow.
[1913 Webster]
WordNet (r) 3.0 (2006):
snowdrift
n 1: a mass of snow heaped up by the wind