"Wandering thoughts" refers to when our mind starts to drift or wander away from our current focus, leading us to think about other things unrelated to the present moment. Full definition
There are several things to do about wandering thoughts. (religion-online.org)
Instead, experts say, try meditation that allows you first to recognize wandering thoughts and then to bring your focus back to the present. (discovermagazine.com)
Whenever I do have a free moment, my mind is usually wandering thinking up ways I can decorate (and re-decorate) our suburban Florida home. (makinghomebase.com)