tubtub
For someone (actor umi- & inst) to bump his own or someone else's head (theme i-) against an object (loc ref), as by holding a child and bumping the head as one passes by a protruding object.
For someone (actor -um-) to hit someone's head or a part of it (loc ref -an), with an object held such as a stone, board (theme i-).
panubtub; manubtub
For someone (agent) to use something(inst paN-) for hitting, as described above.