Entry 1 sense Webster, 1913 Workday /wẽrk'-dāˌ/ · Work·day · IPA /wˈɜrkdˌeɪ/ 01 n. & a. A day on which work is performed, as distinguished from Sunday, festivals, etc., a working day. 1. A day on which work is performed, as distinguished from Sunday, festivals, etc., a working day.