Trepidation rhymes with:
intimidation, liquidation, accommodation, backwardation, commendation, consolidation, degradation, depredation, fluoridation, foundation, fundacion, gradation, intimidation, inundation, invalidation, liquidation, oxidation, predation, recommendation, retardation, sedation, validation
Trepidation sounds like:
tarbutton, trafton, trefethen, trevathan