adjectiveaidiacht1expensivecostasachadj1cmudaoradj1cmuit could prove costlyd'fhéadfadh sé a bheith costasach2valuable, preciouscostasachadj1cmudaoradj1cmuluachmharadj1cmucostly jewelleryseodra luachmharcostly winesfíonta daora3causing 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