A lawyer grilling Brian Mulroney last week suggested that he had not been "fulsome" in his responses. Rather than questioning what the lawyer meant by this adjective, Mulroney just denied whatever the accusation was. "I am being fulsome, and truthful," said the former prime minister.
The scene recalls Howard Cosell's 1967 interview with a cocky Muhammad Ali. "You're being extremely truculent," said Cosell. "Whatever truculent means," replied Ali, "if that's good, I'm that."
Truculent was actually the apt word in that case, whereas no one seems to agree on what exactly fulsome means. Grammarians sputter against its alleged misuse, but its uses are actually various and even contradictory. The first definition in U.S. dictionaries tends to be the popular one: something like copious, generous, well-developed (which is the sense I think the lawyer was groping for with Mulroney).
And in music or food writing, it tends to mean rich (sopranos are often in fulsome voice; wine sometimes has fulsome sweetness). But they go on to list alternate meanings offensive, overdone, excessively complimentary and end with a note on the history and changing meanings of the word, admitting that the first sense is disputed.
Most working copy editors, though, are not nearly so permissive: They will usually strike a line through any use of fulsome that is not intentionally negative. The Oxford English Dictionary admits no debate either: Fulsome means simply overly flattering or cloying. The usage note reads, "In 'fulsome praise,' fulsome means excessive, not generous." In other words, whatever it means, it's not good. Mr. Mulroney does not want to be it.
Usage guides fret over whether the meaning of the word is changing due to frequent current use in the positive sense. We hear the word so many times meaning "full" that perhaps the copy editors are losing the battle. After all, Ronald Reagan once told a press conference that he had had "a very fulsome apology from the president of Iraq" and he meant no snark by it. If the president of the United States embraces a meaning, it tends to stick.
The U.S. college professor Paul Brians has a clear and useful website called Common Errors in English; his entry on fulsome says that to some people it means offensively overdone, and to others it means generous. He comments, "The first group tends to look down on the second group, and the second group tends to be baffled by the first. Best to just avoid the word altogether." This sensible advice is a point that even pedantic usage guides make: The chief problem with this word now is simply ambiguity. If no one knows what it means, then it's just not useful.
It should be noted, though, that there are quite a few words in English that have both positive and negative senses, or frankly contradictory senses. Cleave, for example, can mean to stick to or to split apart, which is just delightfully nonsensical. And it's still a lovely word, so no one will suggest we delete it from the lexicon because of this idiosyncrasy. Adumbrate means both to outline and to cast a shadow over; buckle means to fasten or to give way; dust means to remove dust from or to pour dust onto. These are called Janus words, or auto-antonyms or contranyms. (Conversely, flammable and inflammable mean the same thing. I don't know what you call words like these. False antonyms?) We can live with all this weirdness in the language, as long as we are aware of it. I suspect that fulsome will also come to be accepted, but mostly in its positive sense.
Interestingly, some words that sound similar to fulsome also cause confusion. I once, trying to be clever, described an Ascot tie as being fulminant. This would be dangerous neckwear, as fulminant means coming on with great speed and severity (it is usually used of a disease). An eruption of violent criticism can be described as fulminating. I was probably confused by the sound of "full" and fulsome actually does come from the Middle English "full," whereas fulminate and fulminant come from the Latin for lightning. What I was grasping for was that the tie was particularly luxuriant (large, spreading or florid, not to be confused with luxurious, expensive, although it may have been both). So, prone to mistakes as I am, I will not fulminate against fulsome, but give a full accounting of my errors, especially when on the witness stand.