C-4

noun (1)
\ ˈsē-ˈfȯr How to pronounce C-4 (audio) \

Definition of C-4

 (Entry 1 of 6)

: a high explosive composed of various chemicals that make it moldable and plastic Before it was detonated, I held a piece of C-4 plastic explosive about the size of a baseball. It felt slightly greasy and granular, but otherwise indistinguishable from my daughter's Play-Doh.— Eric Schlosser

4-F

noun (2)
\ ˈfȯr-ˈef How to pronounce 4-F (audio) \

Definition of 4-F (Entry 2 of 6)

: classification as unfit for military service also : a person having this classification

4-H

adjective
\ ˈfȯr-ˈāch How to pronounce 4-H (audio) \

Definition of 4-H (Entry 3 of 6)

: of or relating to a program set up by the U.S. Department of Agriculture originally in rural areas to help young people become productive citizens by instructing them in useful skills (as in agriculture, animal husbandry, and carpentry), community service, and personal development

2,4-D

noun (3)
\ ˌtü-ˌfȯr-ˈdē How to pronounce 2,4-D (audio) \

Definition of 2,4-D (Entry 4 of 6)

: a white crystalline irritant compound C8H6Cl2O3 used especially as a weed killer

2,4,5-T

noun (4)
\ ˌtü-ˌfȯr-ˌfīv-ˈtē How to pronounce 2,4,5-T (audio) \

Definition of 2,4,5-T (Entry 5 of 6)

: an irritant crystalline compound C8H5Cl3O3 used especially formerly chiefly as an herbicide and defoliant

helium-4

noun (5)

Definition of helium-4 (Entry 6 of 6)

: helium

Other Words from C-4

Adjective

4-H'er \ ˈfȯr-​ˈā-​chər How to pronounce 4-H'er (audio) \ or less commonly 4-Her noun

First Known Use of C-4

Noun (1)

1964, in the meaning defined above

Noun (2)

1942, in the meaning defined above

Adjective

1926, in the meaning defined above

Noun (3)

circa 1945, in the meaning defined above

Noun (4)

1946, in the meaning defined above

History and Etymology for C-4

Adjective

from the fourfold aim of improving the head, heart, hands, and health

Noun (3)

di-

Noun (4)

tri-

Noun (5)

helium + 4, mass number of the isotope

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Dictionary Entries near C-4

c'mon

C++

c3

C-4

CA

Ca

ca

Statistics for C-4

Look-up Popularity

Time Traveler for C-4

The first known use of C-4 was in 1926

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More Definitions for C-4

4-H

adjective

English Language Learners Definition of 4-H

: of or relating to a government program in the U.S. that teaches farming skills and good citizenship to young people

Comments on C-4

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