Pearl
late Middle English: from Old French perle, perhaps based on Latin perna ‘leg’, extended to denote a leg-of-mutton-shaped bivalve.
wiktionary
From Middle English perle, from Old French perle of uncertain etymology. Probably via unattested Medieval Latin *pernula, from Latin perna(“ haunch; a marine bivalve shaped like a leg of lamb”) [1] but also derived from Medieval Latin perla, from Latin perula(“ little bag”). Its typographic use follows the name given by Jean Jannon to the type used in his miniature editions of Vergil, Horace, & the New Testament in the 1620s, which were the smallest printed works to his time. Its surfing use derives from the supposed resemblance to pearl diving.
etymonline
pearl (n.)
"nacreous mass formed in the shell of a bivalve mollusk as a result of irritation caused by some foreign body," early 14c., perle (mid-13c. as a surname), from Old French perle (13c.) and directly from Medieval Latin perla (mid-13c.), which is of unknown origin. Perhaps from Vulgar Latin *pernula, diminutive of Latin perna, which in Sicily meant "pearl," earlier "sea-mussel," literally "ham, haunch, gammon," so called for the shape of the mollusk shells.
Other theories connect it with the root of pear, also somehow based on shape, or Latin pilula "globule," with dissimilation. The usual Latin word for "pearl" was margarita (see margarite).
Used from 14c. of anything valuable or of the finest kind; from mid-15c. of something small, round, and glistening white. For pearls before swine, see swine. Pearl Harbor translates Hawaiian Wai Momi, literally "pearl waters," so named for the pearl oysters found there; transferred sense of "effective sudden attack" is attested from 1942 (in reference to Dec. 7, 1941).
pearl (v.)
late 14c., "to adorn with pearls," from pearl (n.). From 1590s as "to take a rounded form" (intrans.); from c. 1600 as "to make into a form, or cause to assume the form and appearance, of a pearl" (trans.). Related: Pearled; pearling.
