1
general::
Phrase(s): beg off (on something)
to ask to be released from something; to refuse an invitation. • I’m sorry, but I’ll be out of town on the day of your party. I’ll have to beg off on your invitation. • I have an important meeting, so I’ll have to beg off., Phrase(s): beg something off
to decline an invitation politely. • She begged the trip to the zoo off. • We all begged off the dinner invitation.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Ask to be released from an obligation; turn down an invitation. For example, He's asked me out to dinner three times already, but I have to beg off again, or Mother couldn't take on another committee and so she begged off. [Early 1700s]
American Heritage Idioms