Hi All,
It is not an abbreviation.
Omoa, a village, in the parish of Bertram-Shotts, Middle ward of the county of Lanark, 5 miles (S. W.) from the village of Bertram-Shotts ; containing 206 inhabitants. This place is situated in the south-western part of the parish, and owes its origin to the erection of considerable iron-works, in 1787, on the estate of Colonel Dalrymple; the ironstone in the neighbourhood is very abundant, and the ore is wrought to a great extent. The village lies on the road from Airdrie to Cambusnethan.
There is a place called Omoa in Honduras, may have been named after that.
Tom