1. fill sb in on something; pass on information to sb who missed it
bring them up to speed on the new plan
To 'get up to speed' with something means to move at the same pace as something else or to be well informed or knowledgeable about something, especially when it comes to details or the latest information. "Jennifer needs to get her typing up to speed. She's producing considerably less than everyone else." "Can you bring Hazel up to speed on the latest changes? She hasn't been here for a while." This idiomatic expression can be heard in social and professional situations.