Lisp function for evaluating a function on a list of arguments.

(apply func arg1 ... argk arglist)
applies func to the list (arg1 ... argk . arglist).

A few examples will make this clear:

(apply #'+ '(2 3 4 5)) ⇒ 14
(apply #'+ 2 3 '(4 5)) ⇒ 14
The second form (k>0) is almost never seen, but Common Lisp defines it.

func may also be a symbol (e.g. '+ instead of #'-); the definition of that symbol as a function is then used (it must exist, of course).