And you'd still be using the wrong one if you use Webster's. The correct (inasmuch as anything can be correct in this world - correct for me!) choice is the compact edition of the Oxford English Dictionary, which is quite possibly the most glorious duology of volumes of infinitesimally minuscule type ever published, from Aa to Zyxst. Many happy childhood evenings of eyestrain and ebullient exclamations of sesquipedalian rhapsody.
It even comes with a magnifying glass.