a.

1. 每月的；每月一次的；一个月有效的[B]
   a monthly season ticket

   一张月票

   The rent on his apartment was his biggest monthly expense.

   公寓的租金是他每月最大的一笔开支。

ad.

1. 每月；每月一次
   Some magazines come out monthly.

   有的杂志每月出一期。

n.

1. 月刊[C]
2. 【口】月经[P]

adj.

adv.

n.

1. a magazine that is published once a month.
2. (monthlies) informal a menstrual period.