infanta

Hmm... is there an open italics someplace here? (just askin'.)

I had a little nut tree,
Nothing would it bear
But a silver nutmeg,
And a golden pear;
The King of Spain's daughter
Came to visit me,
And all for the sake
Of my little nut tree.

Her dress was made of crimson,
Jet black was her hair,
She asked me for my nut tree
And my golden pear.
I said, "So fair a princess
Never did I see,
I'll give you all the fruit
From my little nut tree.
Children's Nursery Rhyme
(sounds a bit phallic to me)

In this case the folk etymology is itself probably a folk etymology. The Elephant and Castle district once housed a smithy belonging to the Cutlers' Company; cutlers used ivory for their knife handles; to indicate this the smithy used a sign of an elephant, which in heraldry is depicted with a castle on its back (an alteration of the howdah); a pub later appeared on the spot and used the elephant and castle sign too; and from this the district was named. There was never an Infanta of Castile in British history, and that story about one is presumably a fanciful invention like those about Port Over Starboard Home or Sir Loin—what the linguist Larry Horn has called etymythology.

There is a district of London called "Elephant & Castle", centred on a pub of that name. It is said that this is in fact a corruption of "Infanta de Castile",