disjointed (adj.)

1580s, of words or speech, "incoherent;" 1640s in the literal sense of "having the joints separated;" past-participle adjective from obsolete verb disjoint "separate or disconnect the joints of; disrupt, destroy" (mid-15c.), from Old French desjoint, past participle of desjoindre, from Latin disiungere, from dis- (see dis-) + iungere "to join together," from nasalized form of PIE root *yeug- "to join." Related: Disjointedly; disjointedness.