To nim is to continuosly restlessly move one part of your or body while the rest remains still, ie foot, leg, knee, hand etc.
I was sat in the coffee house nimming whilst waiting for my friend....
To nim is to dawdle or loiter around an object and/or innocent person, providing an obstruction of severe nuisance value.
We planned to purchase some tomato soup in the supermarket, but unfortunately were blocked by an elderly lady nimming in that particular aisle.
After lunch, Baz and his reprobate chums went off to nim about in front of the war memorial.