darkness, disappear, shade, informal, grow dark, be blinded
暗 centers on the absence of light: literal darkness, growing dark, or being blinded. The informal sense extends from things done in the shadows, away from open visibility.
暗 combines 日 (sun) and 音 (sound), but the historical origin is phono-semantic: 音 provides the sound アン, and the original meaning relates to darkness or being closed off from light.
The sun 日 is blocked by sound 音, as if noise itself casts a shadow. When the sun is hidden, everything falls into darkness.
For アン, imagine an unlit room so dark you can't see your own hand: 'un-' (アン) as in 'unseen' or 'unlit', tying the sound directly to the absence of light.
dark; gloomy; murky
assassination
code; password; cipher
darkness
darkness
darkness; the dark
pitch-dark; pitch-black; completely dark
hint; suggestion; clue; implication
memorization; memorisation; learning by heart
tacit; unspoken; implicit
secret manoeuvres (maneuvers); operating behind the scenes
code; cipher; password
dim; gloomy
implicitly; indirectly; tacitly; by implication; obscurely
suspicion will raise bogies; once you suspect something, everything else will look suspicious; jumping at shadows
light and darkness; light and shade
recitation; reciting from memory
(theatrical) blackout
dark side (of nature, town, etc.)
concealed pung; concealed three-of-a-kind