It’s about time. We are now on Instagram!
1570s, from un- (1) "not" + kempt "well-combed, neat," from variant past participle of Old English cemban "to comb," from Proto-Germanic *kambijan, from *kamb- "comb" (see comb). Form unkembed is recorded from late 14c. The verb kemb is rare after 1400s, but its negative past participle form endures.