Folk etymology

Description
Folk Etymologies are false explanations of word origins that have been modified from their true form over time.

Examples

 * 1) cockroach-- This word comes from the Spanish word cucaracha, where cuca means "kind of caterpiller". Another version says that cuca is a variation of caca which means "excrement", since cockroaches "eat and defile with their ill-scented dung" (Captain John Smith, 1624, "Virginia).
 * 2) "rule of thumb"-- This phrase more-or-less means "a rough meausrement", but urban legend has it that this phrase came about because it was a law that a man could legally beat his wife with a stick no thicker than his thumb. This rule was never even around.
 * 3) bridegroom--This word comes from the Old English word "brideguma" where guma means man. Over the years, groom was put in instead because it meant boy, lad, or groom.
 * 4) female--this word is often thought of as the opposite of male, where "fe" is a negation-type term. "Female", as a matter of fact, comes from the French Femelle, meaning "small or dear woman". Since "female" has often been used in contrast to "male", over the years, the people have just assumed that "fe" is a negation/opposite term.