dark

1 dark /ˈdɑɚk/ adjective
darker; darkest
1 dark
/ˈdɑɚk/
adjective
darker; darkest
Britannica Dictionary definition of DARK
[also more dark; most dark]
1 
: having very little or no light
— opposite light
2 
: not light in color : of a color that is closer to black than white
3 
of a color : having more black than white : not light — opposite light
4 
of a person's hair, eyes, skin, etc. : black or brown in color
— opposite fair
5 
: less light in color than other things of the same kind — see also dark chocolate, dark meat
6 
: lacking hope or happiness
7 
: bad or evil
8 
: dealing with unpleasant subjects such as crime, war, unhappy relationships, etc.
9 
: full of mystery — see also dark horse
10 
of a place : not known or explored because it is far from where most people live
11 
of a voice : low and full in sound

cast a dark cloud

— see 1cloud

darkest hour

— see hour

— darkish

/ˈdɑɚkɪʃ/ adjective [more darkish; most darkish]
2 dark /ˈdɑɚk/ noun
plural darks
2 dark
/ˈdɑɚk/
noun
plural darks
Britannica Dictionary definition of DARK
1 
the dark
a  : a state in which no light can be seen
b  : a place where little or no light can be seen
2 
[noncount] : the time of day when night begins : the time when the sky becomes dark for the night
3 
darks [plural]
a  : dark colors : colors that are more black than white
b  : dark clothes : clothes that are black, dark brown, etc.

in the dark

1 
: in a state in which something is hidden or kept secret
2 
: in a state of not knowing about something
— see also leap in the dark at 2leap, shot in the dark at 1shot, whistle in the dark at 2whistle