riáis
Riáis is a Spanish verb form. Specifically, it is the second-person plural imperative (vosotros/vosotras) form of the verb reír. Reír is an irregular verb in Spanish that means "to laugh." The imperative mood is used to give commands or make requests. Therefore, "riáis" translates to "laugh" when addressing a group of people informally (vosotros/vosotras).
The verb reír belongs to the third conjugation, ending in -ir. Its conjugation in the imperative is
The form "riáis" is used in Spain when speaking to a group of people you would address