the reigning king (used following a name or in the titles of lawsuits, e.g. Rex v. Jones: the Crown versus Jones)

a helmet boldly inscribed with the initials GR (George Rex) for George III

Justice Wilmot's unpublished 1765 judgment in Rex versus Almon

a cat, rabbit, or guinea pig of a breed with very fine short fur

the Cornish Rex is considered a good breed for those with allergies

Rexes are known for their dense, plush coat which feels exactly like velvet