The other two defenitions are bull. Colateral is civiliians getting killed by military action . Colateral when involving civilians can be the same as friendly fire.
When the helicopters rocket was firedshrapnel from the explosion killed a civilian
The hypothetical man (often a sinistercharacter who decided not to go to boot camp) that is doing your girlfriend/wife while you are on deployment overseas.
Ain't no use in goin home,
Jody's got your girl and gone.
Ain't no use in goin back,
Jody's got your Cadillac,
Ain't no use in feeling blue,
Jody's took your checkbook too.