dozens
n. C / Un. a large number of something, usually in groups of twelve. You use this when you want to say there are many of something without giving an exact count.
n. a large but unspecified number of people or things, typically occurring in multiples of twelve. Used as a plural noun to indicate abundance or a significant quantity.
There are dozens of people waiting in line for the concert.
The storm caused dozens of trees to fall across the main road, blocking traffic for several hours.
Despite the complexity of the new software, dozens of independent developers have already created custom plugins to extend its basic functionality.
When used to mean 'many', it is always plural and followed by 'of' before a noun phrase.
I saw dozens peopleI saw dozens of peopleWhen 'dozens' is used as a noun to mean a large number, it must be followed by the preposition 'of'.