nouns - Is “troop” unique among English words in meaning both a group and an individual member of that kind of group?

The term "troop" can mean a group of soldiers, or it can mean an individual soldier (perhaps in this usage it was originally short for "trooper").

In fact, in modern usage, the plural "troops" almost always refers, not to multiple groups, but to multiple individuals. "Obama's surge sent 30,000 more troops to Afghanistan" means 30,000 soldiers, not 30,000 troop-sized groups of soldiers.

Are there any other nouns like that in English, where it can refer to either a group or an individual member of that kind of group? I'd be especially interested in hearing of examples where the plural form of the noun almost always refers to individuals (not groups) in modern usage.

Answer

"The canon" can mean the body of works accepted as canonical by a group; "a canon" can mean one precept of a group; and "the canons" can mean the collection of all precepts which a group follows. In some cases, "the canon" will be the same as "the canons" of a given group, if all of their canonical works concern their canons. Of course, for many groups which have a canon, their canon is a greater collective body of works which do not solely concern their canons. But I think it's similar in usage to your "troop" example.