HOW TO USE THE DICTIONARY

To look up an entry in The American Heritage Dictionary of the English Language, use the search window above. For best results, after typing in the word, click on the “Search” button instead of using the “enter” key.

Some compound words (like bus rapid transit, dog whistle, or identity theft) don’t appear on the drop-down list when you type them in the search bar. For best results with compound words, place a quotation mark before the compound word in the search window.

guide to the dictionary

deep

(dēp)

adj. deep·er, deep·est

a. Extending far downward below a surface: a deep hole in the river ice.

b. Extending far inward from an outer surface: a deep cut.

c. Extending far backward from front to rear: a deep walk-in refrigerator.

d. Extending far from side to side from a center: a deep yard surrounding the house.

e. Far distant down or in: deep in the woods.

f. Coming from or penetrating to a depth: a deep sigh.

g. Sports Located or taking place near the outer boundaries of the area of play: deep left field.

2. Extending a specific distance in a given direction: snow four feet deep.

3. Far distant in time or space: deep in the past.

a. Difficult to penetrate or understand; recondite: a deep metaphysical theory.

b. Of a mysterious or obscure nature: a deep secret; ancient and deep tribal rites.

c. Very learned or intellectual; wise: a deep philosopher.

d. Exhibiting great cunning or craft: deep political machinations.

a. Of a grave or extreme nature: deep trouble; deepest deceit.

b. Very absorbed or involved: deep in thought; deep in financial difficulties.

c. Profound in quality or feeling: a deep trance; deep devotion.

6. Rich and intense in shade. Used of a color: a deep red.

7. Low in pitch; resonant: a deep voice.

8. Covered or surrounded to a designated degree. Often used in combination: waist-deep in the water; ankle-deep in snow.

9. Large in quantity or size; big: deep cuts in the budget.

10. Sports Having a sufficient number of capable reserve players: That team is not very deep.

adv.

1. To a great depth; deeply: dig deep; feelings that run deep.

2. Well along in time; late: worked deep into the night.

3. Sports Close to the outer boundaries of the area of play: played deep for the first three innings; ran deep into their opponents' territory.

1. often deeps

a. A deep place in land or in a body of water: drowned in the deep of the river.

b. A vast, immeasurable extent: the deep of outer space.

2. The extent of encompassing time or space; firmament.

3. The most intense or extreme part: the deep of night.

4. The ocean.

5. Nautical A sounding that falls between marks on a lead line and thus corresponds to an estimated depth rather than a precise depth.

Idioms:

deep down

At bottom; basically: Deep down, she was still a rebel.

in deep water

In difficulty.

[Middle English dep, from Old English dēop; see dheub- in the Appendix of Indo-European roots.]

deeply adv.

deepness n.

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

American Heritage Dictionary Products

HOW TO USE THE DICTIONARY

THE USAGE PANEL

AMERICAN HERITAGE DICTIONARY APP

THE AMERICAN HERITAGE DICTIONARY BLOG

INTERESTED IN DICTIONARIES?

Indo-European & Semitic Roots Appendices

American Heritage Dictionary Products