It’s simple really. It’s a Latin word meaning, “void”, “empty” or “shadowy”. As a third year student of Classical Latin, I picked it as an online nomen, and it stuck.
Contrary to what your eyes may lead you to believe, it’s not a double entendre. In English, we get the word “inane”, meaning silly, stupid or worthless.
“Caput tuum in ano est?”, however, is definitely also Latin, and definitely contains the word you were probably thinking about.
Lingua latina omnium linguarum… or something like that.