Quick, define "disinterested." If you said "impartial" rather than "uninterested," congratulate yourself on knowing the original meaning, albeit one that's eroding. Ben Yagoda at Slate tackles the age-old linguistic issue of knowing when it's OK to let words evolve—and when it's not. But he doesn't just carp about the problem, he provides an algorithm, or at least "a somewhat arbitrary metric," that ranks particular words.
- Disinterested: Stick with the original "impartial."
- Fulsome: Ditch the original "offensively excessive" for the newer "abundant; full."
- Nonplussed: Stick with the original "perplexed" instead of "unfazed; nonchalant."
- Fortuitous: Ditch the original "accidental; unplanned" for the newer "lucky."
Click for more examples
and to see where words rank.