source: https://movebetweenraindrops.tumblr.com/post/87786861935

adjective (quieter, quietest)

1. making little or no noise:

〈人･物が〉静かな, 音を立てない(↔ noisy)

e.g. the car has a quiet, economical engine

〖be ～〗 〈人が〉黙っている, 口をきかない(silent)

e.g. I was as quiet as I could be, but he knew I was there.

(of a place, period of time, or situation) without much activity, disturbance, or excitement:

〈場所･状況･時間が〉閑静な, 平穏な,人気（ひとけ）のない, 物静かな(↔ noisy); 心配のない, くつろいだ

e.g. the street below was quiet, little traffic braving the snow.

without being disturbed or interrupted:

e.g. all he wanted was a quiet drink.

2. carried out discreetly, secretly, or with moderation:

e.g. we wanted a quiet wedding

e.g. I'll have a quiet word with him.

(of a person) tranquil and reserved by nature; not brash or forceful:

〈性格が〉寡黙な, 控えめな, おとなしい

e.g. his quiet, middle-aged parents.

attributive expressed in a restrained or understated way:

e.g. Molly spoke with quiet confidence.

(of a color or garment) unobtrusive; not bright or showy.

〈色･服などが〉落ち着いた, 地味な(↔ loud)

absence of noise or bustle; silence; calm:

静けさ, 閑静; 沈黙(silence)

e.g. the ringing of the telephone shattered the early morning quiet.

freedom from disturbance or interruption by others:

e.g. he understood her wish for peace and quiet.

a peaceful or settled state of affairs in social or political life:

平穏, 安静.

e.g. after several months of comparative quiet, the scandal reerupted in August.

verb chiefly North American

make or become silent, calm, or still:

…を静かにさせる, なだめる(down); 〈恐怖･不安など〉を和らげる(｟主に英｠ quieten)

e.g. with object : there are ways of quieting kids down

静かになる(down)

e.g. no object : the journalists quieted down as Judy stepped onto the dais.

see life.

keep quiet (or keep someone quiet)

refrain or prevent someone from speaking or from disclosing something secret.

refrain from disclosing information about something; keep something secret.

informal without anyone knowing or noticing; secretly or unobtrusively.

see grave1.

(of a person or animal) extremely quiet or docile.

Middle English (originally as a noun denoting peace as opposed to war): via Old French, based on Latin quies, quiet- ‘repose, quiet’.