Many thanks, Frances. So it is likely to be a nickname indicating either that he was new to the area, or had come from a northern parish, to differentiate him from all the other local Kelly families.
At least it firmly links Thomas living and marrying in Maughold, but born c.1775 Ballaugh, to Patrick and Esther in Ballaugh.

And with the MI you posted for Patrick Kelly, Colin now knows that his xgt grandfather was born c.1749 and was of the Daullaugh Mooar, Ballaugh.
(Does this match up at all with the gill place name given in Esther's 1800 will? If not, he could have moved on during the next 29 years.)

Sue