m. a coined
term meaning intellectually or mentally straining or distressing, such as a
problem that is extremely difficult to
resolve.
Mind here is used to mean that from which the
ability or
capacity for reasoning,
thinking or applying one's
knowledge originates. To wrench means to injure (a limb or other
body part) by excessive or violent twisting, turning or stretching so that the affected part is forced out of its
normal position. Used figuratively, wrench means to
cause distress or
pain to someone or something. Thus, if something were
mind-wrenching, such as a
problem one was trying to figure out, it would (figuratively)
twist or stretch or
cause great distress, strain or
pain to the
mind.