It is spelled with a capital L in the example I quoted, and when used with as capital it it means pertaining to Lent and it can mean meagre according to Webster, as in Lenten fare. However used in conjunction with main has me puzzled. The term mains is used for the inbye land of a farm and may be a corruption of mansion More possibles for Lentren here , again odd if used in conjunction with main, could be a misprint for manse which could come over as mainse to a listener.
Giok