What is the opposite word of Quiescent?

Answer: Active

'Quiescent' means inactive, quiet, or dormant.

'Active' means engaged in action, lively, or not inactive, so it is the antonym of 'quiescent'.

• Example with quiescent: The quiescent volcano showed no signs of eruption for decades.

• Example with active: After seismic tremors, the volcano became active and erupted.