You didn't say if the Fred Greenough you were looking for might coincide with the dates of this Joseph J. Greenough.I don't have record of whether the Fred Greenough on our tree married and if so who or if they had children so can't confirm match that way.
I understand the Greenough's came from England in the1700's to the Boston area.Some went to North Carolina while 4 brothers came to NS with a priest to flee US.One of the 4 brothers, James (1819-1879) married Mary Ann Young and had 8 children.
This was Fred and 7 siblings, Soffia(1844-1933), Joseph J.(1858-1940), Eliza, Agnes, Henry, Charlie, and Mary Ann.Joseph J. is the head of my tree so I have lots of info on him down.They were all born in Petpeswick, NS.
Hope this helps confirm or rejects a match for you.