marcus — Saint. Also, Mark. died a.d. 336, pope 336.
porpoise — any of several small, gregarious cetaceans of the genus Phocoena, usually blackish above and paler beneath, and having a blunt, rounded snout, especially the common porpoise, P. phocoena, of both the North Atlantic and Pacific.
purpose — the reason for which something exists or is done, made, used, etc.
tortoise — a turtle, especially a terrestrial turtle.
Three-syllable rhymes
all-purpose — You use all-purpose to refer to things that have lots of different uses or can be used in lots of different situations.
on purpose — the reason for which something exists or is done, made, used, etc.
Four-or-more syllable rhymes
gopher tortoise — any North American burrowing tortoise of the genus Gopherus, especially G. polyphemus, of the southeastern U.S.: several species are now reduced in number.
habeas corpus — a writ requiring a person to be brought before a judge or court, especially for investigation of a restraint of the person's liberty, used as a protection against illegal imprisonment.
multipurpose — able to be used for several purposes: a multipurpose lawn spray.