fe·ri·a (fîr'ē-ə, fěr'-) n.
pl.fe·ri·as or fe·ri·ae (-ē-ē') A weekday on a church calendar on which no feast is observed.
[Medieval Latin fēria, ordinary day, weekday, from Late Latin, feast day (used with ordinals to name the days of the week), from Latin fēriae, religious festival, holidays; see dhēs- in Indo-European roots.] fe'ri·al adj.