Its a word with many connotations in tango.
To be heavy: The way the majority of Argentine teachers describe having connection with the floor. Where ballroom dancing seeks to glide above the floor tango dancers seek purchase and make the floor their friend. In this way the partners communicate the presence of their feet.
Heavy: Sometimes used to describe someone’s embrace indicating their ability to communicate the heaviness of their lower half through their embrace.
Heavy: Literally being heavy and pulling or leaning down on your partner. Extremely incorrect technique.
Heavy: Being sluggish and unresponsive to the lead. A mistaken interpretation of the notion of resistance in the embrace.