beat/bash someone's brains out/in

: to strike repeatedly:

: to hit repeatedly so as to inflict pain

: to walk on : tread

: a single stroke or blow especially in a series

: a sound produced by or as if by beating (see ¹beat)

: a driving impact or force

: being in a state of exhaustion : exhausted

: sapped of resolution or morale

: of, relating to, or being beatniks

: beatnik

: to strike violently : hit

: to attack physically or verbally

: crash

: a forceful blow

: a festive social gathering : party

: try, attempt

: some person : somebody

: the portion of the vertebrate central nervous system enclosed in the skull and continuous with the spinal cord through the foramen magnum that is composed of neurons and supporting and nutritive structures (such as glia) and that integrates sensory information from inside and outside the body in controlling autonomic function (such as heartbeat and respiration), in coordinating and directing correlated motor responses, and in the process of learning — compare forebrain, hindbrain, midbrain

: a nervous center in invertebrates comparable in position and function to the vertebrate brain

: intellect, mind

: to kill by smashing the skull

: to hit on the head

: in a direction away from the inside or center

: outside

: from among others

: eject, oust

: to identify publicly as being such secretly

: to become publicly known

used as a function word to indicate an outward movement

: situated outside : external

: out-of-bounds

: situated at a distance : outlying

: outside

: one who is out of office or power or on the outside

: an act or instance of putting a player out or of being put out in baseball

: in a manner that exceeds or surpasses and sometimes overpowers or defeats