The weeds have 'run riot' over our poor garden. [=the weeds in our garden have grown quickly and have taken over the garden]
The field was a 'riot' of wildflowers. [=the field was filled with many kinds of wildflowers]
The news about the election caused/started/sparked a 'riot' in the city.
(..) out on a limb here, but my friend Natalie is recently single, and... Oop. No, no, no, get off the limb right now. No limb. Come on, she's a riot! She sings karaoke, she has a lot of free time, looks aren't that important to her... No, Jills, that is not happening. (..)2013 Despicable Me 2