The Collaborative International Dictionary of English v.0.48:
Trestlework \Tres"tle*work`\, n. A viaduct, pier, scaffold, or the like, resting on trestles connected together. [1913 Webster]WordNet (r) 3.0 (2006):
trestlework n 1: a supporting structure composed of a system of connected trestles; for a bridge or pier or scaffold e.g.