As Marcella Frank mentions in his Modern English book, collective noun is a word for group of people, animals or objects considered as a single unit. Else where he mentions that collective nouns are countable. According to these definitions words such as "equipment" and " machinery" are collective nouns so they can used as plural nouns but these words do not have plural form. Do you think it is better to omit objects from this definition?
This definition holds true for other categories, doesn't it?
Equipment and machinery are't collective nouns; they are simply uncountable. I'm not sure how omitting 'objects would improve the definition..