Webster's Revised Unabridged Dictionary · 1913

Dim

Dim , adjective

[Anglo-Saxon dim; akin to OFries. dim, Icelandic dimmr: compare Middle High German timmer, timber; of uncertain origin.]

1.
Not bright or distinct; wanting luminousness or clearness; obscure in luster or sound; dusky; darkish; obscure; indistinct; overcast; tarnished.
The dim magnificence of poetry. — Whewell
How is the gold become dim! — Lam. iv. 1
I never saw The heavens so dim by day. — Shakespeare
Three sleepless nights I passed in sounding on, Through words and things, a dim and perilous way. — Wordsworth
2.
Of obscure vision; not seeing clearly; hence, dull of apprehension; of weak perception; obtuse.
Mine eye also is dim by reason of sorrow. — Job xvii. 7
The understanding is dim. — Rogers

Obvious compounds: dim-eyed; dim-sighted, etc.

Dim , transitive verb

1.
To render dim, obscure, or dark; to make less bright or distinct; to take away the luster of; to darken; to dull; to obscure; to eclipse.
A king among his courtiers, who dims all his attendants. — Dryden
Now set the sun, and twilight dimmed the ways. — Cowper
2.
To deprive of distinct vision; to hinder from seeing clearly, either by dazzling or clouding the eyes; to darken the senses or understanding of.
Her starry eyes were dimmed with streaming tears. — C. Pitt

Dim , intransitive verb

To grow dim. — J. C. Shairp