A two cock mouth. Used in the porn industry to describe actresses, and actors, with a wide mouth, large enough to suck at two penises at the same time.
"S(he)'s got a TCM, lets use her (him) for the orgy scene."
An acquaintance of mine was pointing out some of the women walking
in the town square the other day. He made the following statement
about a real beautiful one - " See her, she's great, tcm "