Departure
Noun and する verb
いつだつ
任務を逸脱する行為は慎み給え。
Please refrain from tasks that deviate from the mission.
If you deviate from the plan and undress yourself, that's a serious deviation and could ruin everything! You need to wear pants, you know!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.