Definition: A rule in a number of field team sports designed to help ensure players move together as a tea.
(I don’t think it applies to American football, a game in which large people in Spandex mill around, embracing and bumping into each other in a random pattern)
In New Zealand, it has other connotations.
If you’re dealing with Tasman District Council and you hire someone to interact with them on your behalf, people will say “Oh good, they’re onside with council” which mean that they’ll do council’s bidding without question, forgetting entirely that YOU’RE paying their bill and that they should be representing YOUR interests.
If they’re “offside” with council, they’ll represent your interests, but you’ll get nowhere REALLY fast.
This guy appears to have got seriously offside with the folks who run the boysenberry stall on SH60 just before our turnoff.
Don’t know what he did, but no more boysenberries for him….