monthlya.1. Continued a month, or a performed in a month; as, the monthly revolution of the moon.()2. Done, happening, payable, published, etc., once a month, or every month; as, a monthly visit; monthly charges; a monthly installment; a monthly magazine.()Monthly nurse, a nurse who serves for a month or some short time, esp. one which attends women after childbirth.()n. A publication which appears regularly once a month.()adv.1. Once a month; in every month; as, the moon changes monthly.(Shak.)2. As if under the influence of the moon; in the manner of a lunatic.(Middleton.)