From The Collaborative International Dictionary of English v.0.48 :
Side-slip \Side"-slip`\, v. i. See Skid, below. [Webster 1913 Suppl.]From WordNet (r) 3.0 (2006) :
sideslip n 1: an unexpected slide [syn: skid, slip, sideslip] 2: a flight maneuver; aircraft slides sideways in the air [syn: slip, sideslip]