I am simply trying to get this URL:
http://foo.com/entry/random-entry-123
to redirect to:
http://foo.com/random-entry-123 <
Assuming no further rewrites are in use, and all links inside /entry/ are to rewritten, then try this:
/entry/
RewriteEngine on RewriteBase / RewriteRule ^/entry/(.+)$ /$1 [L,QSA]
Lose the [L] if there are further rewrites ahead in the file.
[L]