Is it ensure, insure, or assure?
Old English scilling, a coin consisting of a varying number of pence (on the continent, a common scale was 12 pennies to a shilling, 20 shillings to a pound), from Proto-Germanic *skillingoz- (cf. Old Saxon, Danish, Swedish, Old Frisian, Old High German skilling, Old Norse skillingr, Dutch schelling, German Schilling, Gothic skilliggs).
Some etymologists trace this to the root *skell- "to resound, to ring," and others to the root *(s)kel- (1) "to cut" (perhaps via sense of "shield" from resemblance or as a device on coins; see shield (n.)). The ending may represent the diminutive suffix -ling, or Germanic -ing "fractional part" (cf. farthing). Old Church Slavonic skulezi, Polish szelang, Spanish escalin, French schelling, Italian scellino are loan-words from Germanic.
former English and British coin, nominally valued at one-twentieth of a pound sterling, or 12 pence. The shilling was also formerly the monetary unit of Australia, Austria, New Zealand, and Ireland. Today it is the basic monetary unit in Kenya, Somalia, Tanzania, and Uganda.