Uncanon (also uncanonical, noncanon, non-canon, noncanonical) is that which contradicts, ignores, and disobeys canon. Being out of character counts as uncanon.
Badly done uncanonicity is a charge. In some cases the act of being uncanon is not bad. It can and does happen in fanfiction, though that of course depends on the skill of the writer.
"Begone, uncanon!" is a regularly heard part of the standard Bad Slash Agent's exorcism chant.