There’s some debate about who said it first, but I’ll vote with the majority and give credit to Mark Twain for this sage bit of writing advice.
“The difference between the right word and the almost right word is the difference between lightning and a lightning bug.”
The right word is the word that conveys the meaning you want to convey and is understood by the reader with a minimum of explanation. Start by thinking about your reader and his or her situation. Get clear about what you want them to do when they’re done reading. Then choose the right words to make that happen
The right word conveys your meaning
This one is simple. Any word that doesn’t convey the meaning you want is the wrong word. You can’t compromise on this. If there’s no single word that will work, you may need to do some defining and explaining.
The right word will be understood by your audience
If you’re writing for a niche audience you can use the jargon they use. Jargon can help you get your message across in a minimum number of words. But if you use a jargon phrase incorrectly, your credibility flies right out the window.
Sometimes there’s more than one right word
There’s almost always more than one way to convey a message. Try to come up with a number of them and use the one that does the best job.