Mon"day (?), n. [OE. moneday, monenday, AS. monandaeg, i.e., day of the moon, day sacred to the moon; akin to D. maandag, G. montag, OHG. manatag, Icel. manadagr, Dan. mandag, Sw. m�x86;ndag. See Moon, and Day.]

The second day of the week; the day following Sunday.

© Webster 1913.