I've thought about it some more and I've ruled out the last one. So, now it's between Merriam Webster's Collegiate Dictionary and American Heritage's College Dictionary. The American Heritage one was published 2 years ago (1 year older than the Merriam Webster's one), will that be an issue with the dictionary?
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.