1. (non-pejoratively, uncommon use) To fervently subscribe into a cause or belief with passion and energy.
2. (pejoratively, common use) To heavily buy into a cause or belief that is utterly doomed to failure and disgrace with complete disregard to all reasoning, evidence, and intuitions that clearly indicate such a result. Referring to an inability or unwillingness of someone to be persuaded out of believing obvious nonsense -- even when confronted with the facts -- often times out of a sense of loyalty to a group identity even if there is no reason to do so. Generally implies the complicity of an individual or a group of people in their own deception irregardless of whether or not they realize it.
2. (pejoratively, common use) Karen is so crazy that she's investing money in Sears and for some bizarre "reason" thinks that they will be "restored to their former glory." She's sure into drinking the kool-aid.
A) Well, it's a can of Coors, brewed from a mountain stream. It'll set your insides on fire and make your kidneys scream. Sure is fine.
B) A song by Johnny Paycheck, one of the original outlaws of the 1970's, featured on his 1977 album "Take This Job and Shove It."
A crazy giant beverage who breaks through walls in order to save humans from the minor inconvenience of thirst. Has the inability to use normal methods of entry, such as the door or gate. Has caused over 900 trillion dollars worth of property damage in his lifetime.
"oh yeah"(distant)
me: wtf was that? did you hear that?
CRASH!! "OH YEAH"
me: dude! my fucking roof!!
Any poisonous, liquid concoction one drinks, in order to commit suicide. Taken from the infamous "Jonestown massacre" mass suicide, when cult leader Jim Jones killed his flock with poisoned punch.