1. Not agitated; without losing self-possession; SYN. unagitated.
2. Characterized by absence of emotional agitation; SYN. serene, tranquil.
3. Marked by freedom from agitation or excitement.
4. (Of weather) Free from storm or wind.

In a softened tone; SYN. muted, subdued, quiet.

ETYM Of imitative origin. Related to Mumble.
Failing to speak or communicate etc when expected to; SYN. silent.

1. Free of noise or uproar; or making little if any sound.
2. Characterized by an absence or near absence of agitation or activity.
3. Not showy or obtrusive; SYN. restrained.
4. (Astronomy; of the sun) Characterized by a low level of surface phenomena like sun spots e.g.

ETYM Latin silens, -entis, p. pr. of silere to be silent; akin to Goth. ana-silan.
1. Marked by absence of sound; SYN. soundless, still.
2. Having a frequency below or above the range of human audibility.
3. Not made to sound; SYN. unsounded.
4. (Of film) Having no spoken dialogue and usually no soundtrack.

1. Free from noticeable current
2. Not sparkling; SYN. noneffervescent.
3. Used of pictures; of a single or static photograph not presented so as to create the illusion of motion; or representing objects not capable of motion

ETYM Latin tacitus, p. p. of tacere to be silent, to pass over in silence; akin to Goth. thahan to be silent, Icel. thegja, Old High Germ. dagęn: cf. French tacite. Related to Reticent.
Done or made in silence; implied, but not expressed.
Silent; unspoken; merely implied.

1. With little or no sound.
2. With little or no activity or especially agitation; ('quiet' is a nonstandard variant for 'quietly' as in); SYN. quiet.

In a silent manner.

In a tacit manner; by unexpressed agreement.