adj. 1
Not busy; lacking activity.
I'm just sitting here with a desk of cards, enjoying a slow afternoon.
v. 1
To keep from going quickly; to hinder the progress of.
adv. 1
Slowly.
That clock is running slow.
n. 1
Someone who is slow; a sluggard.

Related words

Word family: sloth slowball slowcoach slowcore slowly slow-moving slowness slow-walk
Phrases: slow-down slow up slow as molasses slow motion slow one's roll digital slow motion slow burner slow cooker

Forms

Plural: slows → slow-downs, delayings…
Past participle: slowed
e.g. slowed → retarded, delayed, hindered, slackened…

Slow, Backward or Averse?

A man may be slow or backward in entering upon that to which he is by no means averse.

J. C. Fernald, English Synonyms and Antonyms (1914)

Use in printed books, per decade from 1850 to 2019.

3 letters: dim¹
4 letters: long¹, late¹, easy², dumb¹, lazy², dull¹
5 letters: heavy², quiet², delay², relax², dense¹, slack¹, inert², tardy², pokey², chary²
6 letters: behind², simple², stupid², slowly², boring², steady², retard², hinder², obtuse², stolid², torpid², draggy², unbusy
7 letters: careful², gradual³, tedious³, prudent², languid², irksome², laggard², unready, slacken², tardily
8 letters: moderate³, cautious², inactive³, delaying³, sluggish², tiresome³, plodding², dilatory⁴
9 letters: leisurely³, lethargic³, ponderous³, wearisome³
10 letters: deliberate⁴, decelerate⁴, languorous
13 letters: uninteresting⁴

The small number after each word is its number of syllables (easy² = 2 syllables).