(n.) The faculty or capacity of the mind for forming ideas; the exercise of this capacity; the act of the mind by which objects of sense are apprehended and retained as objects of thought.

IQ abstract thought act of thought apprehension brainwork caliber capacity cerebration clairvoyance cogitation command comprehension conceit conception conceptualization creative thought deductive power esemplastic power excogitation foreknowledge grasp grip headwork heavy thinking idea imageless thought integrative power intellect intellection intellectual exercise intellectual grasp intellectual power intellectualism intellectuality intellectualization intelligence intelligence quotient knowledge mastery mental act mental age mental capacity mental grasp mental labor mental process mental ratio mentality mentation mother wit native wit noesis power of mind precognition prehension ratiocination rationality reasoning reasoning power sanity savvy scope of mind sense straight thinking thinking thinking aloud thinking out thinking power thought understanding wisdom wit