When in a male/female marriage, the "wife" used to be a man, is a transexual, or is in transition. A wife/husband. Wife + Husband = wusband. Also Was-a-Husband.
'Hey! Is that Walter over there? Do you think he brought his wife?' 'Oh! You mean his "wusband." She was a he!'
Originates as a rhyming slang from bukkake. It refers to smoking crack on a tin foil plate placed on your partner's vagina. However, this practice can be very painful if you don't vaporize your gear properly.