— verb (used with object), dec·i·mat·ed, dec·i·mat·ing.
to destroy a great number or proportion of: The population was decimated by a plague.
to select by lot and kill every tenth person of.
Obsolete . to take a tenth of or from.
Straight from my dictionary dot com app.
Yes, originally, decimate meant to reduce by a half, but at least according to dictionary.com, that is am obsolete definition.
It can also refer to a specific Roman punishment for groups of people (most often in reference to legion). A practice that is terribly brutal despite any reference to small fractions.
However, I think the first definition is the one in most common usage, in english, today.
