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

know

(nō)

v. knew(n, ny), known(nōn), know·ing, knows

v. tr.

1. To perceive directly; grasp in the mind with clarity or certainty.

2. To regard as true beyond doubt: I know she won't fail.

3. To have a practical understanding of, as through experience; be skilled in: knows how to cook.

4. To have fixed in the mind: knows her Latin verbs.

5. To have experience of: “a black stubble that had known no razor” (William Faulkner).

a. To perceive as familiar; recognize: I know that face.

b. To be acquainted with: He doesn't know his neighbors.

7. To be able to distinguish; recognize as distinct: knows right from wrong.

8. To discern the character or nature of: knew him for a liar.

9. Archaic To have sexual intercourse with.

v. intr.

1. To possess knowledge, understanding, or information.

2. To be cognizant or aware.

Idioms:

in the know Informal

Possessing special or secret information.

know full well

To have complete knowledge of; understand completely: You know full well you're supposed to take off your shoes when you come inside.

know (someone) in the biblical sense

To have sexual relations with (someone).

you know Informal

Used parenthetically in conversation, as to fill pauses or educe the listener's agreement or sympathy: Please try to be, you know, a little quieter. How were we supposed to make camp in a storm like that, you know?

[Middle English knouen, from Old English cnāwan; see gnō- in the Appendix of Indo-European roots.]

knowa·ble adj.

knower 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