ninepence (n.)

"the sum of nine pennies," 1540s, from nine + pence. No coin of this value was ever issued in England, but the silver shilling issued by Queen Elizabeth for Ireland in 1561 were current in England for nine pence, and in New England it was the name of a Spanish silver coin worth about 9 pence of New England currency.

The ninepence was a coin formerly much favoured by faithful lovers in humble life, as a token of their mutual affection. It was for this purpose broken into two pieces, and each party preserved with care one portion, until on their meeting again, they hastened to renew their vows. [John Gough Nichols, "Anecdotes of the English Coinage," in The Numismatic Chronicle, 1839]