/ Dictionary / Index O oystershell scale: Meaning and Definition of Find definitions for: oys'ter•shell scale" Pronunciation: (oi'stur-shel"), [key] a scale insect, Lepidosaphes ulmi, having a scale shaped like the shell of an oyster, which infests various deciduous trees and shrubs. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. oyster plant oysters Rockefeller Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language