Changing word definitions

[JaredL]

Anybody know when the word troop changed from a group of soldiers to a soldier?

I remember early in the Iraq war I got pretty upset upon learning that a troop had died (every [censored] guy in the unit died? WTF?!?!) now I've gotten quite used to it.

I'm guessing there are other examples, but using the word troop to refer to a single soldier is pretty bad since it's done all the time by broadcast journalists who are paid 6 and probably in some cases, 7 figures by the biggest news outlets.