Meaning
To return to a topic, question, or discussion point at a later time after gathering more information.
Three examples from work
Meeting pacing
PMWe don't have the API latency numbers yet; let's circle back on this tomorrow.
LeadI'll pull the production logs and have concrete metrics ready.
Stakeholder inquiry
ClientCan we support single sign-on with Azure AD?
Tech LeadI believe so, but let me circle back with our security team to confirm our SAML configuration.
Stand-up coordination
DevI will circle back with you after stand-up to help debug that Docker networking issue.
ColleagueAppreciate it; I'm free all morning.
Idiomatic business phrase: 'Let's circle back on this'. Politer and more professional than saying 'I don't know right now'.