discussion (n.)youdaoicibaDictYouDict
mid-14c., "examination, investigation, judicial trial," from Old French discussion "discussion, examination, investigation, legal trial," from Late Latin discussionem (nominative discussio) "examination, discussion," in classical Latin, "a shaking," from discussus, past participle of discutere "strike asunder, break up," from dis- "apart" (see dis-) + quatere "to shake" (see quash). Meaning "a talking over, debating" in English first recorded mid-15c. Sense evolution in Latin appears to have been from "smash apart" to "scatter, disperse," then in post-classical times (via the mental process involved) to "investigate, examine," then to "debate."
psychometrics (n.)youdaoicibaDictYouDict
"science of measuring mental processes," 1917, from psychometric; also see -ics.
subconscious (adj.)youdaoicibaDictYouDict
1823, "not wholly conscious, feebly conscious" (implied in subconsciously), from sub- + conscious. First attested in De Quincey. The noun, in the psychological sense ("mental processes taking place without consciousness"), is attested from 1886, from adjectival sense "occurring in the mind, but not in consciousness;" earlier noun was subconsciousness (1845).