An onboarding buddy is a peer of a new employee who’s assigned to help them get through the first X months of employment in the company or team.
At Futurice, I had a great buddy and I was a buddy for a bunch of people.
I find it helpful to have a peer because sometimes there are questions you don’t feel comfortable asking a supervisor/manager and often peers know more of the organisational silent knowledge that’s relevant to the position or being new at the company.