What does "working day" mean?

Any of those days of a week on which work is done, officially Monday to Friday in many countries (even though many people work on weekends).

What is a synonym for "working day"?

Common synonyms include: weekday, feria, full work day, jobday, work day, workday.

noun

noun ·Rare ·Advanced level

Noun

1
Any of those days of a week on which work is done, officially Monday to Friday in many countries (even though many people work on weekends). UK, mainly
"It will take five working days to process your application."
2
the amount of time that a worker must work for an agreed daily wage wordnet
3
The part of a day in which work is done; the number of hours one must work per day for a specified wage. UK, mainly
"Your working day is 8 hours."
4
a day on which work is done wordnet

"It will take five working days to process your application."