The Collaborative International Dictionary of English v.0.48:
Rouser \Rous"er\, n. 1. One who, or that which, rouses. [1913 Webster] 2. Something very exciting or great. [Colloq.] [1913 Webster] 3. (Brewing) A stirrer in a copper for boiling wort. [1913 Webster]WordNet (r) 3.0 (2006):
rouser n 1: someone who rouses others from sleep [syn: waker, rouser, arouser]