obsolete At a point in time that shall never come to pass; never. Refers to Lammas Day (August 1), the feast day of the new harvest in the Northern Hemisphere and a "cross-quarter day" on which rents were due. Thus, to be paid on "latter Lammas" meant to never be paid at all. Primarily heard in UK. I have my tenants and their dues in good order, but I fear that some are planning to pay at latter Lammas.