qua·ter·na·ry
ˈkwä-tər-ˌner-ē 
ˈkwä-tə-,
kwə-ˈtər-nə-rē
1
a
: of, relating to, or consisting of four units or members
b
: of, relating to, or being a number system with a base of four
2
Quaternary
: of, relating to, or being the geologic period from the end of the Tertiary to the present time or the corresponding system of rocks see Geologic Time Table
3
: consisting of, containing, or being an atom bonded to four other atoms
plural quaternaries
1
Quaternary
: the Quaternary period or system of rocks
2
: a member of a group fourth in order or rank
Examples of quaternary in a Sentence
Recent Examples on the Web
Lauren Jarvis-Gibson,
Charlotte Observer,
25 June 2026
Meanwhile, 24 eateries, including a local cafe, received citations for health code violations such as brown residue in the ice machine, a lack of quaternary ammonia test strips and improperly cooled food.
—
Veronica Fernandez-Alvarado
may 15,
Sacbee.com,
15 May 2026
No quaternary ammonia chemical test kit.
—
Gege Reed,
Louisville Courier Journal,
26 Sep. 2025
New encoding schemes and measurement bases could be developed based on the mathematics of the quaternary structure, increasing resilience against technical imperfections and side-channel attacks.
—
Pravir Malik,
Forbes.com,
19 Sep. 2025
See All Example Sentences for quaternary
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Adjective
Read labels for fragrance disclosures and ammonium quaternary compounds.
—
Lauren Jarvis-Gibson,
Charlotte Observer,
25 June 2026
Meanwhile, 24 eateries, including a local cafe, received citations for health code violations such as brown residue in the ice machine, a lack of quaternary ammonia test strips and improperly cooled food.
—
Veronica Fernandez-Alvarado
may 15,
Sacbee.com,
15 May 2026
No quaternary ammonia chemical test kit.
—
Gege Reed,
Louisville Courier Journal,
26 Sep. 2025
New encoding schemes and measurement bases could be developed based on the mathematics of the quaternary structure, increasing resilience against technical imperfections and side-channel attacks.
—
Pravir Malik,
Forbes.com,
19 Sep. 2025
See All Example Sentences for quaternary
Cite this Entry
“Quaternary.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quaternary. Accessed 6 Jul. 2026.
Copy CitationMedical Definition
quaternary
1 of 2 adjective
qua·ter·na·ry
ˈkwät-ə(r)-ˌner-ē
kwə-ˈtər-nə-rē
kwə-ˈtər-nə-rē
: consisting of, containing, or being an atom bonded to four other atoms
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