Is “Eyebrow” a Scrabble word?

1.The hair that grows over the bone ridge above the eye socket.

2.A dormer, usually of small size, whose roof line over the upright face is typically an arched curve, turning into a reverse curve to meet the horizontal line at either end.

3.A clump of waste fibres that builds up in a roller machine.

1.To build up waste fibres in a roller machine.

2.To signal with one's eyebrows.