Spanner

(plural spanners)

(Australian, NZ, British, Irish) A hand tool for adjusting nuts and bolts.Pass me that spanner, Jake; there's just one more nut to screw in.
(rare) One who, or that which, spans.

1915, Florence Kiper Frank, The Jew to Jesus: and other poemsThe scheme of the spanner of continents and the desire of the little husbandman hoarding for his loved ones...

(weaponry) A hand tool shaped like a small crank handle, for winding the spring of a wheel lock on a musket.

1786, Fig. 10. The spanner for spanning or winding up the spring of the wheel lock. — Francis Grose, A Treatise on Ancient Armour and Weapons, page xvi.

(obsolete) A device in early steam engines for moving the valves for the alternate admission and shutting off of the steam.
(UK) A problem, dilemma or obstacle; something unexpected or troublesome (in the phrase spanner in the works)Halfway through the production of Macbeth, the director found that the stage was smaller than he expected. This really threw a spanner in the works.
(British, Irish, mildly derogatory) A stupid or unintelligent person; one prone to making mistakes, especially in language.You spanner, Rodney! I wanted a Chinese, not an Indian!