The difference between Quiescent and Still

When used as adjectives, quiescent means inactive, quiet, at rest, whereas still means not moving.

Still is also noun with the meaning: a period of calm or silence.

Still is also adverb with the meaning: without motion.

Still is also verb with the meaning: to calm down, to quiet.

check bellow for the other definitions of Quiescent and Still

Quiescent as an adjective:

Inactive, quiet, at rest.

Examples:

"The bats were quiescent at that time of day, so we slowly entered the cave."
Quiescent as an adjective (orthography):

Not sounded; silent.

Examples:

"The k is quiescent in "knight" and "know"."
Quiescent as an adjective (cell biology):

Non-proliferating.

Still as an adjective:

Not moving; calm.

Examples:

"'Still waters run deep."
Still as an adjective:

Not effervescing; not sparkling.

Examples:

"still water; still wines"
Still as an adjective:

Uttering no sound; silent.
Still as an adjective (not comparable):

Having the same stated quality continuously from a past time
Still as an adjective:

Comparatively quiet or silent; soft; gentle; low.
Still as an adjective (obsolete):

Constant; continual.

Still as an adverb:

Without motion.

Examples:

"They stood still until the guard was out of sight."
Still as an adverb (aspect):

Up to a time, as in the preceding time.

Examples:

"Is it still raining? It was still raining five minutes ago."

"We've seen most of the sights, but we are still to visit the museum."
Still as an adverb (degree):

To an even greater degree.

Examples:

"Tom is tall; Dick is taller; Harry is still taller. ("still" and "taller" can easily swap places here)"
Still as an adverb (conjunctive):

Nevertheless.

Examples:

"I’m not hungry, but I’ll still manage to find room for dessert."

"Yeah, but still..."
Still as an adverb (archaic, poetic):

Always; invariably; constantly; continuously.
Still as an adverb (extensive):

Even, yet.

Examples:

"Some dogs howl, more yelp, still more bark."

Still as a noun:

A period of calm or silence.

Examples:

"the still of the night"
Still as a noun (photography):

A photograph, as opposed to movie footage.
Still as a noun (slang):

A resident of the Falkland Islands.
Still as a noun:

A steep hill or ascent.

Examples:

"rfquotek W. Browne"

Still as a noun:

a device for distilling liquids.
Still as a noun (catering):

a large water boiler used to make tea and coffee.
Still as a noun (catering):

the area in a restaurant used to make tea and coffee, separate from the main kitchen.
Still as a noun:

A building where liquors are distilled; a distillery.

Still as a verb:

to calm down, to quiet

Examples:

"to still the raging sea"

Still as a verb (obsolete):

To trickle, drip.
Still as a verb:

To cause to fall by drops.
Still as a verb:

To expel spirit from by heat, or to evaporate and condense in a refrigeratory; to distill.

Examples:

"rfquotek Tusser"