to jump two "bases" and go directly to bed upon meeting a blind date. In a "job" or 'occupation' to advance ahead to a new professional level not on institutional merit, but on natural skills and talents alone.
Zeke made a bystep in his career as a she-bitch by jumping from male fashion model to xxx award winningporn star and director of a-list celebrity films in one week.
Bas-tee is word you use, when you want to say "Bastard", but are in a place, or around people where you shouldn't use "bastard". Everyone will know what you mean, without being rude lol.