Usually refers to a man. Bitchass is
one who posesses such qualities that usually stem from insecurity, egotism, 'rejection backlash' (cold heartedness, conniving, etc often triggered by 'loss' of psychosomatic support mechanism/network.
ex. A crazy ass man trying to fuck up parts of his soon to be
ex-wife's life.
Bitchasses can be more dangerous than a similar
type female. (Their motives, strategies, goals, etc are different.)
I had never heard someone called a bitchass, until I came up with it as a
word for my husband in 2008.