nodsish 

Verb: Lower and raise one's head slightly and with a degree of halfheartedness or confusion, esp. in confusion, agreeing without really understanding what's going on, partial understanding, or to give someone a signal that one needs an explanation.

Noun: An act of partially nodding the head to express passivity and/or confusion.

Milly: I had bread pudding and then I jumped out of a window into a green pool.
Mike: *nodsish*

Jake: Are you going or aren't you that interested?
Jane: *nodsish*

nodsish by Shad0wless October 28, 2011