adj. thick·er, thick·est
a. Relatively great in extent from one surface to the opposite, usually in the smallest solid dimension; not thin: a thick board.
b. Measuring a specified number of units in this dimension: two inches thick.
2. Heavy in form, build, or stature; thickset: a thick neck.
3. Having component parts in a close, crowded state or arrangement; dense: a thick forest.
4. Having or suggesting a heavy or viscous consistency: thick tomato sauce.
5. Having a great number; abounding: a room thick with flies.
6. Impenetrable by the eyes: a thick fog.
a. Hard to hear or understand, as from being husky or slurred: thick speech.
b. Very noticeable; pronounced: has a thick accent.
8. Informal Lacking mental agility; stupid.
9. Informal Very friendly; intimate: thick friends.
10. Informal Going beyond what is tolerable; excessive.
1. In a thick manner; deeply or heavily: Seashells lay thick on the beach.
2. In a close, compact state or arrangement; densely: Dozens of braids hung thick from the back of her head.
3. So as to be thick; thickly: Slice the bread thick for the best French toast.
1. The thickest part.
2. The most active or intense part: in the thick of the fighting.
thick and thin
Good and bad times: They remained friends through thick and thin.
[Middle English thicke, from Old English thicce; see tegu- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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:
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.