1 adjective expensivecostasach adj1 c m udaor adj1 c m uit could prove costlyd'fhéadfadh sé a bheith costasach2 adjective valuable, preciouscostasach adj1 c m udaor adj1 c m uluachmhar adj1 c m ucostly jewelleryseodra luachmharcostly winesfíonta daora3 adjective causing serious problemsthat was a costly mistake on his partd'íoc sé go daor as an dearmad sin, ba mheancóg mhór é sin aigetheir lack of preparation proved costlyd'íoc siad go daor as a n-easpa ullmhúcháin
