Like for instance someone saying “Gopher John” when answering the phone. What does this mean?
It’s commonly used when you pick up a radio on a public band.
So if you have a jobsite where there are 100 radios, and someone needs to reach Ted, they’ll page the radio and say something like “Hey Ted, do you copy?” and Ted will respond with “Go for Ted,” which means yes, Ted is here and he’s listening, go ahead.
It was used in a small way some 40 years ago and never really caught on.
And, if you’ve reached Gopher Ted, you might respond with “Go for Gopher Ted”
Roger, Roger! What’s our vector, Victor?
Tower to radio clearance, over!
That’s Clarance Over!
What? Huh? Who?!?
And what is Ted supposed to copy?
Signifying that he received a good copy of the message
Bone apple tea
I’m American and I’ve never heard this used.
But after thinking about it, gopher is a play on words that means “go for”. So saying gopher John is like saying “go for John” and can be a greeting.
“Go for X” was somewhat common, including in media. I think OP was mishearing that. There’s virtually no way to differentiate between “gopher” and a rushed, casual “go for” in speech.