It is beyond obvious that you have no idea what a formal definition is. What a delusion is exactly has been determined by psychiatrists and should a belief meet those established criterea, then it is formally to be recognized as a delusion. Just as what a kilogram is is defined by the kilogram standard. It is per definition a certain magnitude of mass. You can come up with your own nonsensical definitions and attempt to convince others to accept them if you like, though I strongly doubt that you'd have much success, given that the current definitions were chiefly set by a collectivity of inidivduals who specialise in the field of what they're trying to define. Thus, for clarity sake, these definitions are taken for granted. All you're doing is confusing others with your pseudointellectual bullshit simply for the reason that you're some kid trying to be edgy.