not bright; obscure from lack of light or emitted light

a dim room; a dim flashlight.

not seen clearly or in detail; indistinct

a dim object in the distance.

not clear to the mind; vague

a dim idea.

not brilliant; dull in luster

a dim color.

not clear or distinct to the senses; faint

a dim sound.

not seeing clearly

eyes dim with tears.

tending to be unfavorable; not likely to happen, succeed, be favorable, etc.

a dim chance of winning.

not understanding clearly.

rather stupid; dim-witted.

to make dim or dimmer.

to switch (the headlights of a vehicle) from the high to the low beam.

to become or grow dim or dimmer. ?

dim out, (in wartime) to reduce the night illumination of (a city, ship, etc.) to make it less visible from the air or sea, as a protection from enemy aircraft or ships. ?

take a dim view of, to regard with disapproval, skepticism

or dismay

Her mother takes a dim view of her choice of friends.

noun

darkness , duskiness , murkiness , obscureness , obscurity