Derogatory term for a rookie soldier [closed]

Nowadays in the US, infantrymen are regularly known as grunts. That said, it may not be quite what you're after, as it relates to their position rather than implying incompetence.

The appropriate word is gomer.

Gomer: military slang. An inept or stupid colleague, especially a trainee.

There are a lot of names for a raw recruit:

What about: greenhorn

• A newcomer, inexperienced, especially one who is unfamiliar with the ways of a place or group.

Can't believe this hasn't been posted. The term used pretty widely across all branches is:

BOOT

It is used as both noun and adjective. F***in' boot, That was a boot move. You're so boot.

It can even be applied to officers. "Boot Lieutenant".