Definition of "protuberance"

For the most part they were small standard gauge 0-6-0 side tanks of the type illustrated, with long tapered chimneys and an unusual feature for the Continent in the shape of domeless boilers, the protuberance just behind the chimney being a sandbox.

1941 August, “Notes and News: The Swiss South Eastern Railway”, in Railway Magazine, page 376

Ever since their creation the Daleks have been attempting to conquer and enslave as much of the universe as they could get their grubby little protuberances on.

1989, Ben Aaronovitch, Remembrance of the Daleks