Comprehensive resource for understanding and mastering English idioms
The idiom "walk out on" means to leave or abandon a situation or person suddenly, without any warning or explanation. It can also mean to reject or turn down an offer or proposal.
The idiom "walk out on" has been used in English since at least the 16th century. It is believed to have originated from the practice of leaving a group or gathering suddenly, without any warning or explanation, by simply walking out the door. Over time, the meaning of the idiom has broadened to include more than just leaving physically, but also leaving emotionally or turning down an offer or proposal.