Completely in agreement with, in favor of, or supporting (something). I'm all for eating healthy foods, but I just can't stand the taste of broccoli. I'm all for seeing a movie this Saturday!
all for something(spoken)
strongly approving of something Americans are usually all for freedom of speech.Related vocabulary: in favor of something
Usage notes: often used in the form I'm all for it: If the new law will keep guns out of the hands of kids, I'm all for it.
Completely in favor of something or someone, as in I'm all for eating before we leave, or The players are all for the new soccer coach. This colloquial phrase was first recorded in 1864.