“You say that your definition of compound words is ‘quirky.’ What do you mean by that?”
It can be very tricky to define exactly what qualifies as a compound word and what does not. Linguistically speaking, any word formed with a prefix or suffix or some other meaningful lexical stem counts. For this site’s purposes, however, we try to limit what we mark as a compound to words formed by concatenating two or more distinct smaller words.
Still, that leaves a lot of room for interpretation and judgment. For instance, do we allow words formed by prepending a- (afloat, agleam, athwart) or be- (befell, belittle, bewitch), prefixes which can themselves be counted as distinct words? We do not, since the meanings of those words do not quite match their meanings as prefixes. On the other hand, we do in many cases count words formed by prepending in- (inborn, inlay, inroad) or out- (outboard, outcry, output), at least where the meaning of the prefix would seem to match its standalone definition. (To be clear, we do not count words like inconvenience, where the prefix indicates negation, or intact, where the word is of wholly foreign derivation.)
By contrast, despite meaning very nearly what they do as standalone words, we do not count words formed with such suffixes as -able, -ably or -ability, since including them would open up such a complicated can of worms. For one thing, while words like bankable or patentable look like nice, well-formed compounds of bank and patent, the spellings of other words are transformed in some way by the presence of the suffix (get to gettable, argue to arguably, live to livability), spoiling the cleanness of the resulting hybrid. For another, there are odd cases like likable and likeable, variants of the same word where only one has the look of a valid compound. And finally, this family of suffixes is no different in function from -ible, -ibly and -ibility, which do not count as standalone words in any way. Once we venture down the -able rabbit hole, where do we stop?
For similar reasons, we do not count words with -fully as a suffix (artfully, colorfully, dutifully), since that would imply words with -ful should also count, when ful is not itself a word. However—perversely, you may say—we do count words formed with -hood (childhood, godhood, nationhood) and -ward (backward, wayward, windward), despite the fact that these suffixes do not mean quite what they do as standalone words, since they are so easy to overlook when working on the puzzle. (When Emerson said, “A foolish consistency is the hobgoblin of little minds,” he couldn’t have known how much solace his words would provide us here at Spelling Bee Solver.)
In fact, if we had to sum up our compound word policy briefly, it would be that we try to offer the most helpful guidance we can without going overboard into madness. This is why we count such words as potlatch, powwow and warlock as compounds, despite the fact that they bear no etymological relationship to the words they appear to be made from. It’s why we count certain formations from such iffy-word prefixes as arch-, aqua-, auto-, kilo-, mega-, micro-, mini-, multi- and photo-, why we count certain other formations from such kinda-word suffixes as -fold, -gram, -kind, -like, -proof and -teen, why we count such not-quite-compounds as ticktock and zigzag, why we count such clipped compounds as biopic, botnet and romcom, and why we make what may seem to be so many other strange and inconsistent judgments. The fact that a word looks like a compound is often what’s most important when a player is stymied by the puzzle.
But we will never count ganglion, which is neither a gang nor a lion.