IPA: /ˈkaʊntərˌræli/
KK: /ˈkaʊntərˌræli/
A gathering of people to express their opposition to another event or demonstration.
The activists organized a counterrally to protest against the policies of the government.
Counterrally → It is formed from "counter-" (meaning against) and "rally" (from Old French *ralier*, meaning to gather or unite). The word "counterrally" means to gather or unite in opposition to something.
Think of gathering 'against' something ('counter-') — that's what a counterrally means.
No commonly confused words.