1) To engage beforehand 
• (v. t.) To engage by previous contract; to bind or attach previously; to preoccupy.
Pre`ën·gage' transitive verb [ imperfect & past participle Preëngaged ; present participle & verbal noun Preëngaging .] To engage by previous contract; to bind or attach previously; to preoccupy. « But he was preëngaged ...
to engage beforehand. · to put under obligation, esp. to marry, by a prior engagement. · to win the favor or attention of beforehand: Other matters preengaged him.