Duplicitous is a word with an appropriately tricky origin. It was originally a legal term for including two pleas in one, which is a no-no. Much like that origin, many terms for the Iago-like and Loki-ish have been lost in the mists of time (or maybe stolen by some rat-brained, two-hearted turncoat). Consider reviving these words the next time you encounter anyone twistical.
This word is usually a compliment, or at least a neutral description of an impressive talent: being equally skilled with both hands. Maybe because the left hand has often been considered disreputable or even Satanic, the word for this ability took a turn. Laurence Sterne’s A Political Romance, published in 1968, gives this word some slimy ilk, describing “A little, dirty, pimping, pettifogging, ambidextrous fellow.”
This term, around since the early 1800s, can be literal or figurative. A winding road can be called twistical, but so can a lying scumbag. The Oxford English Dictionary (OED) definition is deadpan and wonderful: “… not straight or plain in character; morally or mentally tortuous.” An example from David Humphreys’ 1815 book The Yankey in England describes a common problem in sketchy men: “In his dealings with t’other sex, he is a leetle twistical.”
3., 4., 5., AND 6. TWO-HEARTED, DOUBLE-HEARTED, TWO HEARTS AND DOUBLE HEART
Two-faced is a common term for the untrustworthy (and the inspiration for a Batman villain), and the number two is part of many similar terms. An OED example from some 1649 religious literature goes on a guitar solo of dualities: “Unlesse we have two faces, two tongues, two understandings, two judgements, two consciences, two hearts, two pair of hands, two pair of leggs, two purses, which every honest man hath not, we cannot see how it may be done.”
This term is usually literal, describing trains, snakes, and monsters with two noggins. But it’s sometimes been part of the lexicon of duplicity, much like double-hearted.