Unusual Name

There's no townland name in Mayo which bears any similarity to that word, nor have I ever seen it in connection with anyone's name.  Are you able to post a copy of the record here, so that we can see the original?  If not, and it's a record from a parish register, then if you indicate the parish and the date I can look at the record myself.  My grandmother was a McNulty who grew up in East Mayo, and I've already downloaded most of the parish records from that area.

There is an Owenwee town who's Barony is Murisk and the Parish is oughtvale (unsure of spellings sorry)

There is an Owenwee town who's Barony is Murrisk and the Parish is oughvale (unsure of spellings sorry)

As some surnames were often very common in small parishes, nicknames were given to distinguish one family from another.
For instance my grandmothers family were Finns in an area full of Finns, so her family were the Finns Bob, my fathers family are the Duffy Peggs.
Usually named after a grandfather or great grandfather. Sometimes the name of a landmark like a hill or well could be used.