No, it is not witch burning, hamster swallowing or dwarf throwing, it is the sin of being theologically drunk.
Of course, being drunk is a sin in its own right; it is an act of gluttony, one of the Seven Deadly sins and it is a catalyst for many other sins.
Drunkeness comes in many degrees; there's the Irish one of "having drink taken" which is a way of covering the pleasant and (if controlled) harmless stage of having had one or two drinks, just enough to feel a slight quickening of the senses.
Then there is "sloshed," "trolleyed" and all the other epithets we use to describe someone who is pretty well inebriated.
And, finally, the "dead drunk" stage which says it all.
But "theologically drunk" - what is meant by that phrase?
Well, it does not mean an overdose of St Thomas Aquinas; what it does mean is being in such an inebriated state that one is no longer able to distinguish moral values and, therefore, not capable of defending one's faith or recognising when one is committing a sin, the consequences of which are manifest.
This must then fall into the gravest category, that of mortal sin.
For anyone suffering from addiction to alcohol, this definition is not quite so simple.
There are strong forces at work with an addiction and although Archbishop Sheen used to say that "the sin of alcoholism is in the blood" I am fairly certain that a confessor priest would not classify an alcoholic being theologically drunk as being in mortal sin.
Why? Because in committing the sin the person is not in full control of their faculties, deliberate and complete consent (in all probability) are lacking.
But, for the rest of us......being theologically drunk will leave us with both a physical and spiritual hangover.