early 15c., "armed encounter, battle," from Old French conflit and directly from Latin conflictus (see conflict (v.)). Meaning "struggle, quarrel" is from mid-15c. Psychological sense of "incompatible urges in one person" is from 1859 (hence conflicted, past participle adjective). Phrase conflict of interest was in use by 1743.
conflict con·flict (kŏn'flĭkt')
A psychic struggle between opposing or incompatible impulses, desires, or tendencies.