shilling
Pronunciation: /ˈʃɪlɪŋ/
noun

Phrases
-
not the full shilling
- British informal very unintelligent or slow: he’s not the full shilling, but a damn good worker
-
take the King's (or Queen's) shilling
- British enlist as a soldier: not everyone who graduates goes on to take the Queen’s shilling[with reference to the former practice of paying a shilling to a soldier who enlisted]

Origin:
Old English scilling, of Germanic origin; related to Dutch schelling and German Schilling