Stick One's Neck Out Meaning

(idiomatic) To take a risk, putting oneself in a vulnerable position.

Example: 1960, P. G. Wodehouse, Jeeves in the Offing, chapter XVI:
  Uncle Tom's study was a place I seldom entered during my visits to Brinkley Court, because when I did go there he always grabbed me and started to talk about old silver, whereas if he caught me in the open he often touched on other topics, and the way I looked at it was that there was no sense in sticking one's neck out. It was more than a year since I had been inside this sanctum [...]