To use a blackboard to assist in an informal discussion.
A large flat surface, finished with black slate or a similar material, that can be written upon with chalk and subsequently erased; a chalkboard.
To draw into conversation.
To enter into conflict with (an enemy).
To come into gear with.
To enter into (an activity), to participate (construed with in).
To mesh or interlock (of machinery, especially a clutch).
To attract, to please; (archaic) to fascinate or win over (someone).
To guarantee or promise (to do something).
To engross or hold the attention of; to keep busy or occupied.
To arrange to employ or use (a worker, a space, etc.).
To bind through legal or moral obligation (to do something, especially to marry) (usually in passive).
To enter into battle.