Webster's Revised Unabridged Dictionary · 1913

Sad

Sad (sad) , adjective

[Old English sad sated, tired, satisfied, firm, steadfast, Anglo-Saxon saed satisfied, sated; akin to Dutch zat, Old Saxon sad, German satt, Old High German sat, Icelandic saer, saddr, Gothic saþs, Lithuanian sotus, Latin sat, satis, enough, satur sated, Greek 'a`menai to satiate, 'a`dnh enough. Compare Assets, Sate, Satiate, Satisfy, Satire.]

1.
Sated; satisfied; weary; tired. [Obsolete]
Yet of that art they can not waxen sad, For unto them it is a bitter sweet. — Chaucer
2.
Heavy; weighty; ponderous; close; hard. [Obsolete, except in a few phrases; as, sad bread.]
His hand, more sad than lump of lead. — Spenser
Chalky lands are naturally cold and sad. — Mortimer
3.
Dull; grave; dark; somber; -- said of colors.
Sad-colored clothes. — Walton
Woad, or wade, is used by the dyers to lay the foundation of all sad colors. — Mortimer
4.
Serious; grave; sober; steadfast; not light or frivolous. [Obsolete]
Ripe and sad courage. — Chaucer
Lady Catharine, a sad and religious woman.
Which treaty was wisely handled by sad and discrete counsel of both parties. — Ld. Berners
5.
Affected with grief or unhappiness; cast down with affliction; downcast; gloomy; mournful.
First were we sad, fearing you would not come; Now sadder, that you come so unprovided. — Shakespeare
The angelic guards ascended, mute and sad. — Milton
6.
Afflictive; calamitous; causing sorrow; as, a sad accident; a sad misfortune.
7.
Hence, bad; naughty; troublesome; wicked. [Colloquial]
Sad tipsy fellows, both of them. — I. Taylor

Sad is sometimes used in the formation of self-explaining compounds; as, sad-colored, sad-eyed, sad-hearted, sad-looking, and the like.

Collocations (1)
Sad bread , heavy bread. [Scottish & Local, United States] — Bartlett

Sad , transitive verb

To make sorrowful; to sadden. [Obsolete]
How it sadded the minister's spirits! — H. Peters

SAD , noun

Seasonal affective disorder. [Acron.]