flan·nel 
(fl
ăn
əl)
n.1. A soft woven cloth of wool or a blend of wool and cotton or synthetics.
2. flannelsa. Outer clothing, especially pants, made of this cloth.
b. Underclothing made of this cloth.
3. Flannelette.
[Middle English, a kind of woolen cloth or garment, perhaps variant of flanyn, sackcloth, probably from Old French flaine, a kind of coarse wool.]