A few years ago, I was awestruck with the cleverness of this winning clue from the Azed Slip Archive:
The jungly mass one cleaves (7) MACHETE
[M (mass) +ACE (one)] cleaves i.e. holds (THE)*
The whole clue is the definition: a machete is something that cleaves i.e. cuts through the jungly mass.
This clue plays on a special property of 'cleave': the word has two meanings diametrically opposed to each other. The clue's wordplay uses one meaning of 'cleave' (to hold/cling), while its definition uses the opposite (to cut/divide).
Thanks to a Mental Floss article, I found a name for such words with contradictory meanings. They are called contronyms (or contranyms), from the Latin contr[a] (contrary, in opposition) + –onym. Contronyms go by many other names: autoantonyms, antagonyms, or Janus words, called so after the Roman god of beginnings and endings, usually depicted with two faces looking in opposite directions. [T-Rex must be alone in calling them homographic homophonic autantonyms.]
A few examples we use commonly: DUST (to remove dust; to add dust), SCREEN (to show; to conceal), VARIETY (many types; a specific type). The folks at DailyWritingTips have compiled a pretty long list. Many contronyms are formed due to the prefix 'RE-' added to imply 'again': this meaning may contradict a separate meaning. RESIGN (renew a contract; give up on a contract), REPROVE (support or prove again; strongly disapprove), REPLACE (restore to initial position; remove from initial position) are some such words.
As you can guess, contronyms have great potential in cryptic clueing. They make even the basic double definition delightful.
Times 25889: Good or bad (6) WICKED
Independent 8822 (Phi): Spring and fall (4) TRIP
Contronyms can add mystery to the clue's definition.
Guardian 26124 (Nutmeg): Using old Latin in will could be wise or foolish (6) OWLISH
O (old) + L (Latin) in WISH (will). 'Owlish' could mean wise or foolish.
Or they can act as deceptive double-edged indicators.
Can you think of contronyms in other languages? One in Hindi is कल (KAL), which might mean yesterday/in the past or tomorrow/in the future.
A few contronym-based clues for you to solve.
Times 25743: Making harder or softer (9) T________
Times 23609: On right, with fixed agenda, no Democrat! (6) ___G__
Guardian 25731 (Rufus): Certainly less than 50% (3,4) ___ H___
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