köken: Of obscure origin. Sometimes compared to Etymology 2 and 3 below in the sense of "something small." Perhaps related to pin or otherwise borrowed from a substrate language with unshifted p-.
little finger, pinky · a span (unit of measurement)
çekim: çoğul זְרָתוֹת
köken: Borrowed from Egyptian ḏrt (“hand”). Compare Classical Syriac ܙܪܬܐ (zartå, “span; hand”), Ugaritic 𐎏𐎗𐎚 (ḏrt), Classical Mandaic ࡆࡉࡓࡕࡀ (zirta). In the sense of "span", attested in the Tanakh; in the sense "pinky, little finger", attested since the Mishnaic Hebrew period.
pikku + rilli. Many variants exist, including pikkutilli, pikkulilli. The origin is probably simply child speak, but could also be more widely related to finger counting rhymes in Europe. Compare peukalopotti, suomensotti.