Food analogy! If you "eat" too much, you get full... then sick. So to be "fed up(with/from/of something)" is another way of saying you've definitely had enough of a situation. Enough to make you angry, tired, upset, impatient...

I think in standard US English you have to say "fed up with". I've never heard of "fed up of" but that might be fine in other forms of English. It means that you cannot take anymore of the bad situation. You had patience in the past, but now you can't continue. "I'm fed up with the noise the neighbors' children make. I'm going next door to talk to the parents." "He got fed up with being overweight and started an excellent diet and exercise program." "When you become fed up with your boyfriend/girlfriend, you need to leave him/her or else you'll be unhappy."

To be fed up means to have had enough, to have reached the extent of one's patience, usually in a frustrated sense. E.g., "I'm fed up with this job!" = "I've had enough of this job [and am possibly at the point of quitting]!" "She's fed up with her boyfriend" = "She's had enough of her boyfriend [and is possibly dumping him or considering it]."

Hi BRSwartz, I had to check that also! Seems that "fed up of" is particularly British? My first choice is also to say "fed up with". Still, "I'm fed up of going to work in the rain" (for example) makes grammatical sense. As does "fed up with". :)

Tired of Something