From BiblePortal Wikipedia

King James Dictionary [1]

Thin, a. L. tenuis Gr. narrow.

1. Having little thickness or extent from one surface to the opposite as a thin plate of metal thin paper a thin board a thin covering. 2. Rare not dense applied to fluids or to soft mixtures as thin blood thin milk thin air.

In the day, when the air is more thin.

3. Not close not crowded not filling the space not having the individuals that compose the thing in a close or compact state as, the trees of a forest are thin the corn or grass is thin. A thin audience in church is not uncommon. Important legislative business should not be transacted in a thin house. 4. Not full or well grown.

Seven thin ears.  Genesis 41

5. Slim small slender lean. A person becomes thin by disease. Some animals are naturally thin. 6. Exile small fine not full.

Thin hollow sounds, and lamentable screams.

7. Not thick or close of a loose texture not impervious to the sight as a thin vail. 8. Not crowded or well stocked not abounding.

Ferrara is very large, but extremely thin of people.

9. Slight not sufficient for a covering as a thin disguise.

Thin, adv. Not thickly or closely in a scattered state as seed sown thin.

Spain is thin sown as people.

Thin, L. tenuo. See Attenuate.

1. To make thin to make rare or less thick to attenuate as, to thin the blood. 2. To make less close, crowded or numerous as, to thin the ranks of an enemy to thin the trees or shrubs of a thicket. 3. To attenuate to rarefy to make less dense as, to thin the air to thin the vapors.

Webster's Dictionary [2]

(1): ( superl.) Not full or well grown; wanting in plumpness.

(2): ( v. t.) To make thin (in any of the senses of the adjective).

(3): ( superl.) Rare; not dense or thick; - applied to fluids or soft mixtures; as, thin blood; thin broth; thin air.

(4): ( v. i.) To grow or become thin; - used with some adverbs, as out, away, etc.; as, geological strata thin out, i. e., gradually diminish in thickness until they disappear.

(5): ( superl.) Not stout; slim; slender; lean; gaunt; as, a person becomes thin by disease.

(6): ( superl.) Not close; not crowded; not filling the space; not having the individuals of which the thing is composed in a close or compact state; hence, not abundant; as, the trees of a forest are thin; the corn or grass is thin.

(7): ( superl.) Having little thickness or extent from one surface to its opposite; as, a thin plate of metal; thin paper; a thin board; a thin covering.

(8): ( superl.) Slight; small; slender; flimsy; wanting substance or depth or force; superficial; inadequate; not sufficient for a covering; as, a thin disguise.

(9): ( superl.) Wanting in body or volume; small; feeble; not full.

(10): ( adv.) Not thickly or closely; in a seattered state; as, seed sown thin.

Wilson's Dictionary of Bible Types [3]

 Genesis 41:27 (a) The Lord uses this symbol to describe the famine and dearth which was to prevail in Egypt for seven years.