NOT a hairstyle?

I'd have to go with i) skinhead cause, technically, it doesn't actual involve hair.

NOT a Janus word?

All I know is that ii) cleave is not one word. We've got two completely different words that just happen to be spelled the same in Modern English. They come from different IE roots and were spelled differently as recently as a thousand years ago.

Janus was a two faced Roman god. God of doorways.

http://www.pantheon.org/articles/j/janus.html