Double definitions can be among the trickier cryptic clues to crack because they’re the only ones with no wordplay, which is the escape hatch that is supposed to make every clue solvable. We’ll discuss how to make them both easier and harder. (Note that much of this entry is also relevant to writing charade clues.)
First, don’t make all of your double definition clues two words. Some? Definitely. Most? Why not? All? You run the risk of never fooling anyone. A two-word double def with a clear surface is a nifty feat of construction, but almost no other clue can be just two words, so you’re spilling the beans on the clue’s device right away. That’s the opposite of misleading — that risks an auto-solve, and auto-solving is contra the cryptic spirit. A favorite clue of ours from Academy Awardle is a nine-word double definition.
Connecting words between the defintions? Sure. Connecting words are a post all their own, but know that we at the Rackenfracker will use connecting words in a double def. Some people frown on this practice, usually on behalf of the camp that considers connector words an occasional necessary evil that are particularly bad in something that could be as elegant as, sigh, a two-word double definition clue. Again, this is a different post, but that’s not our take. (The hard and fast rule is no nonfunctional words.)
Those, however, are just style issues. The big sign tapper for double definitions (and a lot of charades) is no shared roots. This is a stance shared by every professionally edited US cryptic publication we can think of; you can see it in AVCX’s request for submissions.
But let’s talk about what “no shared roots” means. If we look at the etymology and common English use of each word, and there’s a straight line from one to the other … well, then you’ve got shared root problems. For instance, “Arrest Oliver Twist or David Copperfield (4)” for BOOK is not a double definition, because the verb sense literally means “to write charges in a book.” All those meanings — book a trip, book a band, the restaurant is booked, laws that are on the books — all go back to the same idea of a something into which things have been written; in other words, it’s all the same definition, not a double definition. Chambers Crossword Manual features the quintuple definition clue “Left harbor gate bearing drink (4)” for PORT, but: The left side of a ship is called port because it’s the side that would pull up alongside the harbor a.k.a. port, so named because it’s like a maritime gate/portal/port, which is also how Portugal a.k.a. Portus Cale a.k.a. Cale Port got its name and gave that name to local delicacy oporto a.k.a. port wine, and one’s bearing or comportment or port is how one carries oneself, all from the Latin verb portare (“to carry”) from which the Latin portus (“door”) was originally derived. So “Left harbor gate bearing drink” doesn’t dazzle us with its adroitness — we just see “door door door door door.”
Shared root problems also hit charade clues hard, particularly compound words, prepositions, and prefixes and suffixes. Don’t try to peel the first six letters off of CIRCUMSPECT in order to assemble a charade for CIRCUMNAVIGATE — both mean to circle the thing. BLUEPRINT is not a good candidate for a BLUE+PRINT clue because every meaning of BLUE derives from the color and every meaning of PRINT derives from pressing ink to paper. Prepositions are similar: While BOWL is a legit double def (BOWL as in cereal derives from “blister,” BOWL as in alley derives from “bubble,” and that’s as far as the dictionary takes it although you might wonder if they have a common, more ancient root), a double def of BOWL OVER is not great because there’s no sense in which OVER is not sharing a root. Breaking two-word phrases on the normal break should be saved for special clues where you are 100% certain that you do not have any shared root overlap. (We have examples here but they’re uncommon enough to reserve for some heretofore unpublished puzzles.)
The classic standard is that if a word has two “numbered” dictionary entries, then that’s sufficient to elide shared root problems, but sometimes even that is borderline. We have such a clue in Surface Dive—don’t hover over this next link if you don’t want to see the answer, but our dictionary of record is Merriam-Webster’s and you can see for this entry that verb (2) is distinct from noun (1) and verb (1). Scroll down to “history and etymology” and you’ll see that (1) came from Old English to Middle English to modern English, while (2) came from Old Italian to Middle French to modern English. So the word arrived from two different routes with different meanings: The clue qualifies on paper.
But in that same etymology write-up, you’ll see that they do share the same Latin root. We debated whether that was far “enough” apart, and if your response is to essentially “door door door door door” us, we’d acknowledge that you have a case. This is the nature of Tap the Sign — not a prohibition against use, but a prohibition against common use. If you’re not prepared to argue on its behalf, don’t do it.
Because no shared roots is the standard, by avoiding them, you ensure your solver doesn’t eliminate your intended answer as a possibility because they know it’s shared root and so they go looking for something more disparate. It’s a bit of sloppiness that can tip a potentially great puzzle into a more amateurish, in-over-their-head zone.
Don’t take refuge in “if they have to look it up, the meanings are far enough apart” — that’s 180º wrong. A good puzzle crafter should send their solvers to the dictionary once in a while to stare in amazement that two words they were sure were similarly rooted were in fact distinct. That’s when you are doing it right. But when solvers are given “double definition” clues that actually only have a single def between them, they may tap this sign on their way out the door.