Merriam-Webster's Third New International Dictionary gives
cul-de-sac as "a street that
is closed at one end but usually has a circular area for turning around at that end."
I gave rewording M-W's definition a few tries:
(a) a street that ends in a circular area for turning around at the end;
(b) a street ending in a circular area for turning around;
(c) a dead-end street, lane, etc., having a circular area for...
Would (a), (b) and (c) ever stand a chance of finding their way into an E-Prime only dictionary?