man 2 bind
You need a result from a different section of the manual! Man searches various sections for the information you want. As devnull lists below, the number indicates which section to search.
Incidentally, bind
is a system call, not a C library function. System calls (kernel calls) are in section 2 of the manual, library functions are in section 3.
man man
will tell you how to use the man command!