Answer: brain

AnswerCrossword Clue
BRAINMind.
BRAINVery smart person
BRAINOz scarecrow's desire
BRAINCerebrum.
BRAIN... trust.
BRAINA type of work.
BRAIN... child.
BRAINIntelligence.
BRAIN... storm.
BRAINMain part of the nervous system.
BRAINWhat the Scarecrow wanted.
BRAINWhiz kid
BRAINComputer.
BRAINIntelligence center.
BRAINIntelligent one.
BRAINKind of wave.
BRAINMastermind.
BRAINKind of child
BRAINKind of drain
BRAINKind of storm
brainintelligence
BRAINScarecrow's lack
BRAINRobin Cook book
BRAINCranium's contents
BRAINGray matter
BRAINEinstein
BRAINHigh-IQ sort
BRAINThink tank?
BRAINWoody Allen's "second favorite organ"
BRAINSmart guy
BRAINGenius
BRAINUpper story
BRAINIntellectual
BRAINHit on the head
BRAINJellyfish's lack
BRAINMental giant
BRAINSource of many memories
BRAINSponge's lack
BRAINScarecrow's need
BRAINSmart one, informally