Work function

[Messquito]

3. a large or formal social event or ceremony that is related to work

I suggest this entry because I just found out when you Google work function 99.999% of the results are physics related. Adding this definition would help learners figure out the definition quicker.

 

[Language Hound]

The second entry for function in the WR dictionary is:

a ceremonious public or social gathering or occasion:
a charity function. [countable]

There are many different sorts of functions: charity functions, work functions, etc.
The dictionary cannot list every single one.

 

[Messquito]

Thanks for the comment, but I am not suggesting listing every type of functions, though. Adding this one would surely help clear a lot of confusion.