decimated definition
Wiktionary(0.00 / 0 votes)Rate this definition: 1  decimate(Verb) To kill one man chosen by lot out of every ten in a legion or other military group. 2  decimate(Verb) To reduce anything by one in ten, or ten percent. 3  decimate(Verb) To exact a tithe, or tax of 10 percent.  decimate(Verb) To reduce to one-tenth.