Definition of chalk out:
(v) :
(transitive, figurative) to make (plans); to sketch (something); to describe (a plan).
(v) :
(transitive) To draw or write down (something) using chalk.
(v) :
(US, intransitive, horse racing) In a multi-race wager, to lose to the favorite in all of the remaining races.
(v) :
(US, intransitive, slang) To die.
(v) :
(US, transitive, slang) To kill (someone).