It seems clear that it's 'Months'. There's no 'y' - that's the top of the 'l' from the 'Apoplexy' in the line below.
'Months' also fits in with the normal format of death certs i.e. that the disease or diseases were specified with, after each disease, the length of time it had been present. Thus: Chronic Nephritis - months; Apoplexy - days. Yes, unusual not to have more precision - but at least the medico was consistent!
JAP