Language is communication, but it works only if the communicators understand one other. If you think a word means one thing, and the person you’re talking to thinks it means something else, what we have here is failure to communicate.
Take “fulsome.” Please.
One news report recently noted that Karl Rove, the former Bush strategist, had been at odds with John McCain during the 2000 campaign, when McCain and Bush were both competing for the Republican nomination. But now, the report continued, Rove had changed his tune, and said: “Indeed, as they gathered Saturday over sausages and scrambled eggs at the breakfast sponsored by the South Carolina delegation, Republicans applauded Mr. Rove’s fulsome praise of Mr. McCain.”
Some of you will be thinking, “It’s so nice that Rove is now saying so many nice things about McCain.” But others will be thinking, “So, Rove is up to his old tricks again, heaping insincere compliments on McCain.”
Another publication said that Barack Obama’s introduction of Joe Biden at a rally was “naturally quite fulsome,” implying the introduction was heartfelt and enthusiastic.
That usage of “fulsome,” to mean “ample” or “abundant,” actually fell out of favor in the sixteenth century, though obviously not everyone got the message. The definition of “fulsome” accepted by most language authorities is “disgusting or offensive, esp. because excessive or insincere.”
But what goes around comes around, and as often as not, “fulsome” is being used again to mean “ample,” usually paired with “praise.” While most major dictionaries prefer the “offensive” definition, they all note the common usage of “fulsome” to mean merely “a lot.” Bryan Garner’s Modern American Usage calls “fulsome” a “skunked term,” and the Associated Press stylebook warns against using it in a positive way. (The Oxford English Dictionary, written for British audiences, starts with the “characterized by abundance” definition and goes downhill, through “gross” and “disgusting,” ending with “offensive to good taste.”)
Nonstandard usage is OK—if the context is clear. The problem comes when you’re trying to flatter, and your audience thinks you’re being insincere. So as long as you know that there could be ambiguity with “fulsome,” your best bet is to find another word.