1) Egg yolk 1) Yolky 
• (a.) Of or pertaining to the yolk of eggs; as, the vitelline membrane, a smooth, transparent membrane surrounding the vitellus.
(vĭ-tel´ēn) resembling or pertaining to the yolk of an egg or ovum.
Vi·tel'line adjective [ Latin vitellus the yolk of an egg.] (Biol.) Of or pertaining to the yolk of eggs; as, the vitelline membrane, a smooth, transparent membrane surrounding the vitellus. 
Type: Term Pronunciation: vī-tel′in, -ēn Definitions: 1. Relating to the vitellus. See: yolk sac
vitelline 1. Colored like the yolk of an egg; deep-yellow with a tinge of red. 2. In early use specifically of bile.
Latin vitellus = yolk.