"Oppo" is British naval slang for colleague, I heard it alot from the older navy staff at the Australian Defence Force Academy.

https://www.hmsrichmond.org/dict_o.htm https://en.wiktionary.org/wiki/Appendix:Australian_English_m...

> OPPO > Naval slang - short for opposite number - for the person doing the same job as one's self in another watch or ship. In the former case, since you relieved each other (in the old two-watch days), it behoved you to become friends; thus the word Oppo came to mean Chum. On a two-watch watchbill, the name of a man's 'opposite number' in the other watch was shewn against his own name in the opposite column.

Friend/companion. https://www.merriam-webster.com/dictionary/oppo

Ah, roger that, thanks!

I see that this is a British English word, so it brings to mind the old saying: "Two peoples divided by a common language."

If it helps, I grew up in England and never heard this word either -- sounds like use outside aviation/Navy is rare.

It's archaic, apparently an abbreviation of opposite number. We might use work buddy today, where colleague is too wooden.

Was pretty common to hear amongst the wartime generation, but has declined pretty rapidly since the 80s. Never once heard it used for "sweetheart" as Webster's seems to think.

Coincidentally, not sure if the brand https://en.wikipedia.org/wiki/Oppo was inspired by that, but it certainly fits.