This is the 12631st most frequent Spanish word.
multitudinaria
Very large or massive in terms of attendance or participation.
Here, 'multitudinaria' is used as an adjective to describe the large-scale or massive nature of the demonstration.
La manifestación fue multitudinaria, con miles de personas en las calles.
The demonstration was massive, with thousands of people in the streets.
In this sentence, 'multitudinario' (changed based on grammatical gender) describes a significant scale involving a large gathering of attendees.
Organizamos un evento multitudinario para celebrar el aniversario.
We organized a large-scale event to celebrate the anniversary.
Here, 'multitudinario' conveys the extent of involvement or participation across many individuals or groups nationally.