What Does “A Parcel of Sheep” Mean?
“Parcel” belongs to the same family of old, general-purpose English collective nouns covered elsewhere on this site for deer, treating a group of animals a bit like a bundled lot or package rather than describing any specific behavior. Its application to sheep follows that same broad historical pattern rather than pointing to anything sheep-specific.
A clear, well-documented account of exactly why “parcel” attached itself to sheep in particular isn’t something we could confirm, and rather than invent a tidy explanation, we’d note that many of English’s older collective nouns simply got distributed fairly loosely across multiple animals during the medieval period, when compiling long, varied lists of group words seems to have been something of a popular literary pastime in its own right.
Example: “The old estate ledger recorded a parcel of sheep sold at the autumn market.”
Related: Collective Nouns for Mammals · What Is a Group of Sheep Called?