|Sources||Breacachadh is generally considered to derive from 'breac achadh - speckled field', although PNC (p.327) also gives 'Brochacha', referring to the two castles, one ancient and one more modern.: Hyne dissertation
Breachacha, to-day pr. Breacacha, spotted field. In Martin it is Braki. We also find Brakalli, Brakauch. But Mr Johnston, Coll, says the old people maintained it was originally Brochacha or the like, referring to a broch or borg, or fort. : MacEchern, Place-names of Coll, Transactions, 1906
Breacachadh: MacDougall & Cameron, 1938, map
Tha 'm Breacachadh na fiachalachd: Na Baird Thirisdeach, early 19th C, Orain do Thighearna Chola, 39 [‘m Breac-achadh in ‘Na Baird Leathanaich’]
Ann am Breacachadh thall ud: Na Bàird Leathanaich, Do Thighearna Òg Chola, 69
Breachacha: Place-name Survey Map ARG 50 [the area of land including and to the south of the settlement Breachacha but all the way to Port Garbh ]
I suspect the form folk etymology has come into play here. The map form is Breachacha seems at odds with all the other forms. The name books give no authorities for this spelling.