1. inordinate over-fascination with oneself; excessive self-love; vanity.
2. extreme preoccupation with and indulgence of one's feelings, desires, etc.; egoistic self-absorption.
3. Slang. a contemptibly naive, fatuous, foolish, or inconsequential person.
4. Psychoanalysis. delusional gratification derived from over-admiration of one's own imagined superior physical abilities, usually this solipsistic self-absorption syndrome is outgrown after adolescence, in rare cases will continue into adulthood.

Synonyms:
1. fool, half-wit; imbecile; dolt, dunce, numskull, solipsist, egomaniac, diva, narcissist.

Origin: named after Michael Crabtree, a wide receiver drafted by the San Francisco 49ers as the 10th pick out of Texas Tech in the 2009 NFL Draft. Despite being offered a 20 million dollar contract, he has become the second-longest NFL rookie holdout in two decades.

A person who thinks he's worth a lot more than he really is, especially if he's never proven his worth in the first place.

Someone or something that is of moderate quality.