Buck, pitcher, charged and
battery are just a few examples of equivocal terms. These are words that sound the same (and are spelled the same) yet have completely different meanings. In formal logic, one must avoid using these terms in inconsistent ways. For example:
A buck is worth one hundred cents. Hunter Jones shot a buck with his rifle. Therefore, Hunter Jones shot something worth 100 cents. Logicians would say that we have equivocated on the word "buck", which means one thing in the first sentence, but another in the second.
Equivocal terms show up in popular usage when people make puns. Ty Cobb is a great pitcher, so tip him over and pour me a glass of lemonade. Did you hear about the Energizer Bunny? He was charged with battery. The humor is in the differences between electrical charges and criminal charges, as well as between electrical batteries and the crime of assualt and battery.