reem /ɹiːm/adjective 1noun 1verb 1forms 7 adjective1 •(UK, slang) cool, excellent; desirable; sexy.The cast of The Only Way Is Essex have tried every fake tan in the universe and insist this is best before a reem night out. — 2011 noun1 •A large horned animal in ancient Hebrew literature, variously identified with the wild ox or aurochs (Bos primigenius), the Arabian oryx, or a mythical creature (compare unicorn). verb1 •To open (the seams of a vessel's planking) for the purpose of calking them. formsreemed · reeming · reems · more reem · reemer · most reem · reemest