One day, some day (especially in warning of a negative consequence).

The day of the Sabbath; Saturday, the seventh day of the week.

(obsolete) the Sabbath / (obsolete) Saturday

Alternative spelling of Sabba-day

(of a comic strip) Providing humor in each day's strip, without a plot connecting the various days' respective strips.

(idiomatic) In the current era of history.

A day spent at home, ostensibly in bed, and sanctioned by one's employer/school, when one is feeling stressed or fragile.

plural of day bed

plural of day sign

plural of day laborer