A euphemistic way to refer to an "ass-chewing," a harsh or angry scolding. (When spelling something out with the NATO phonetic alphabet, the words "alpha" and "Charlie" are commonly used for the letters A and C.) The boss is totally going to give us an Alpha Charlie if he hears that we lost that big client.
Alpha Charlie
n. a bawling out; a severe scolding. (Based on AC = ass-chewing. NATO Phonetic Alphabet.) The cop stopped me and gave me a real Alpha Charlie for speeding.