Wool

Wool or fleece was a term for the natural fiber produced on the skin of a sheep, contextually similar but different in certain qualities from hair or fur.

The poem Mary Had a Little Lamb mentioned the lamb as having fleece as white as snow. 

A familiar Earth idiom regarding one having been deceived by another, was the phrase stating how someone had "pulled the wool over my eyes".

Following the discovery of Seska having been a Cardassian agent who served under Chakotay in 2371, left him questioning his ability to judge others. As such, Chakotay asked Tuvok, who also served under him a Starfleet spy, "I'd just like to know, from someone else who pulled the wool over my eyes, was I particularly naive? Was I not paying enough attention? What the hell was it that let all you spies get by me?" Tuvok explained that it was simply his feelings and instincts that had let him down, and further explained that he, too, had never saw anything in Seska that made him suspicious of her, adding, "[s]he quite expertly pulled the wool over my eyes as well." This made Chakotay feel a little better, because in this case "misery loves company". 

Julian Bashir called Admiral William Ross out following the apparent failure of the Section 31 operation on Romulus in 2375, where the operative Luther Sloan was caught and killed by the Tal Shiar, after having figured out that Ross had a part in the operation. Bashir knew that, regarding Sloan, if "[a]nyone clever enough to pull the wool so completely over my eyes wouldn't have been caught by the Romulans so easily," then there was more to the story it appeared, and that he wasn't really dead.