Have consulted my Gaelic speaking Pater,who has in turn double checked with his copy of Dwellys' English Gaelic Dictionary.The definitive work.

His immediate reaction was that where he lives on Lewis 'Fasadh' is pronounced 'FASS-ACH' with a 'throar clearing' sound as the 'ACH',and means 'GROWING'

However,Dwelly defines FASADH as pronounced FASS-EYE,meaning 'PROTRUBERANCE' (growth?) and FIADH as FEE-UH,defined as ' ONE OF THE GROWTH STAGES OF A DEER '

Bet this doesn't help in ANY way,shape,or form......................