: to start to do or deal with (something)
"We need someone to send out the invitations." "I'll get onto it right away."
: to start to talk about something
How did we get onto this topic?
British : to speak to or write to (someone) about a particular problem, job, etc.
I'll get onto the doctor/plumber straightaway and see if he'll come round.
Love words? Need even more definitions?Merriam-Webster unabridged