noun. A tenor voice with a striking dramatic or brilliant quality that is well suited for heroic roles, such as those in Wagnerian opera.

noun. A person with such a voice.

noun. A singer with a deep, strong voice that spans the range between baritone and tenor

"I think I was probably wrong, talking about his Strauss disc the other day, to call him a 'heldentenor' - he may perhaps become one in time next decade's greatest Tristan? and he's still only in his early thirties."