Dictionary.net

• A boy's flannel under-dress, next the shirt: a flannel petticoat.

1899 - The american dictionary of the english language.
By Daniel Lyons

• w[=i]'li-k[=o]t, n. (Scot.) a flannel undervest or petticoat.

1908 - Chambers's Twentieth Century Dictionary of the English Language
By Thomas Davidson