sheer 2 
(shîr)
(shîr)adj. sheer·er, sheer·est
1. Thin, fine, and translucent: sheer curtains; sheer chiffon. See Synonyms at airy.
2.
a. Completely such, without qualification or exception: sheer stupidity; sheer happiness.
b. Free from admixture or adulterants; unmixed: sheer alcohol.
c. Considered or operating apart from anything else: got the job through sheer persistence.
3. Almost perpendicular; steep: sheer rock cliffs. See Synonyms at steep1.
adv.
1. Almost perpendicularly.
2. Completely; altogether.
n.
One that is sheer, such as a curtain.
[Obsolete shere, thin, clear, partly from Middle English shir, bright, clear (from Old English scīr) and partly from Middle English skir, bright, clean (from Old Norse skærr).]
sheerly adv.
sheerness n.