I  looked up the list of CL operators in the HyperSpec, as selected by Paul Graham in his book ANSI Common Lisp

apply      apply function &rest args+ => result*        http://clhs.lisp.se/Body/f_apply.htm

(setq f ‘+) => +
(apply f ‘(1 2)) => 3

aref Accessor AREF  aref array &rest subscripts => element http://clhs.lisp.se/Body/f_aref.htm

(aref (setq alpha (make-array 4)) 3) => implementation-dependent
(setf (aref alpha 3) ‘sirens) => SIRENS
(aref alpha 3) => SIRENS

backquote  (`) The backquote introduces a template of a data structure to be built. Spec

`(cond ((numberp ,x) ,@y) (t (print ,x) ,@y))
is roughly equivalent to writing
(list ‘cond
(cons (list ‘numberp x) y)
(list* ‘t (list ‘print x) y))

block      block name form* => result*Spec 

(block whocares (values 1 2) (values 3 4)) => 3, 4

ceiling   

ceiling and fceiling produce a quotient that has been truncated toward positive infinity; that is, the quotient represents the smallest mathematical integer that is not smaller than the mathematical result.  http://www.lispworks.com/documentation/HyperSpec/Body/f_floorc.htm

(floor 3/2) => 1, 1/2
(ceiling 3 2) => 2, -1

char= 

cons

defmacro

documentation   

eq  eq x y => generalized-boolean  http://clhs.lisp.se/Body/f_eq.htm

(eq ‘a ‘b) => false
(eq ‘a ‘a) => true
(eq 3 3)
=> true

error error datum &rest arguments =>| http://clhs.lisp.se/Body/f_error.htm

(cond ((or (not (typep x ‘integer)) (minusp x))
(error “~S is not a valid argument to FACTORIAL.” x))

expt / exp         Spec perform exponentiation. exp returns e raised to the power number, where e is the base of the natural logarithms. exp has no branch cut. expt returns base-number raised to the power power-number.

(exp 0) => 1.0
(exp 1) => 2.718282
(exp (log 5)) => 5.0
(expt 2 8) => 256

fdefenition 

function 

floor see ceiling

gensym   spec 
get-setf-expansion spec

if 

imagpart 

labels 

length 

multiple-value-bind 
nth-value 

quote 

realpart 

symbol-function 

tagbody 

type-of 

typep 

 aref backquote block car cdr ceiling char= cons defmacro
documentation eq error expt fdefinition function floor gensym
        get-setf-expansion if imagpart labels length multiple-value-bind
        nth-value quote realpart symbol-function tagbody type-of typep