เสียที

sĭia tee

Often heard

RareEveryday

Our takeWorth learning

In a nutshell

About time too! — 'at last,' finally, once and for all.

Particle
1.
It's a particle showing a desire for the action of the statement/question to happen quickly and/or completely, or frustration that it hasn't already happened.
Components2
เสียsĭia
It's a particle implying the verb should be done quickly or completely.
ทีtee
time,occasion,opportunity
Particle
2.
It's a particle implying "just once ; even once".