Pop quiz time! Choose the correct word for each sentence:

Ricky Gervais' clever touch is muted in this unexceptional/unexceptionable film about young men navigating adulthood.

Religious freedom in the U.S. Constitution is unexceptional/unexceptionable.

The judge's ruling was unexceptional/unexceptionable.

The first sentence discusses a film that was ho-hum, nothing exciting, nothing to write home about. Choose unexceptional, and you'll be saying it's plain or ordinary.

The second sentence states that in the U.S., we have religious freedom, period. There are no exceptions, no loopholes. The proper word choice, then, is unexceptionable, meaning without exception or objections.

But what about the third sentence? Was the judge's ruling ordinary or without objections?

Interestingly, both Merriam-Webster Unabridged and Oxford Dictionaries Online say that either answer could mean one of two things. MWU gives a second definition of unexceptional as "allowing no exception; unalterable." If you choose unexceptional, then, MWU would allow for either meaning. ODO, on the other hand, notes that unexceptionable can mean "ordinary." It would allow you to use unexceptionable for either meaning.

Clearly, past writers have confused the meanings of unexceptional and unexceptionable to an extent that meanings are expanding. What's a careful writer to do? To write and speak clearly, we must choose our words with care and be certain our audience understands us. Reserve unexceptional to mean ordinary and unexceptionable to mean without exception or objection.