Term: Slip Image: [{"name":"images\/public\/dictionary\/Slip_fbmpyx0t.jpg","usrName":"Slip.jpg","size":127350,"type":"image\/jpeg","thumbnail":"images\/public\/dictionary\/thSlip_3blwj301.jpg","thumbnail_type":"image\/jpeg","thumbnail_size":45485,"searchStr":"Slip.jpg,!:sStrEnd"}] Definition: A boat berth between two piers or floats. Also, the slight loss of efficient power delivery as a propeller spins in the water.