pre·​treat·​ment | \ ˌprē-ˈtrēt-mənt How to pronounce pretreatment (audio) \
variants: or pre-treatment
plural pretreatments or pre-treatments

Definition of pretreatment

 (Entry 1 of 2)

: an act or instance of treating someone or something in advance : preliminary or preparatory treatment pretreatment of stains pretreatment of a surface for painting pretreatment is often required to remove oil and grease from the waste water.— John H. Sheridan … will allow public works crews to apply salt brine to pre-treat city streets before snow events. The pre-treatment creates an additional layer that helps to melt snow …— Kevin Thompkins A drug called atropine can reverse the effects if administered promptly, and pretreatment with pyridostigmine can help shield the body …— Adam Rogers also : a substance used for such treatment Oils give great shine, but I also use them as a pretreatment to prevent damage prior to coloring my natural hair. — Deena Campbell


variants: or pre-treatment

Definition of pretreatment (Entry 2 of 2)

1 : existing or occurring before treatment the pretreatment period a pretreatment condition the patient's pretreatment drug regimen When treatment was discontinued, the condition of treated nasal muscles quickly returned to pretreatment levels.— Michael Vaiman et al.
2 : of, relating to, or being a pretreatment a waste pretreatment facility/system The current chemical pretreatment process uses relatively harsh conditions to break down the tough structure of grass and other In my weekly Ask a Clean Person columns, I talk a lot about laundry boosters and stain pretreatment products …— Jolie Kerr

First Known Use of pretreatment


1899, in the meaning defined above


1912, in the meaning defined at sense 1

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The first known use of pretreatment was in 1899

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Cite this Entry

“Pretreatment.” Dictionary, Merriam-Webster, Accessed 10 Aug. 2022.

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More Definitions for pretreatment


pre·​treat·​ment | \ -mənt How to pronounce pretreatment (audio) \

Medical Definition of pretreatment

 (Entry 1 of 2)

: preliminary or preparatory treatment unsuccessful … in preventing tumor growth by pretreatment with vitamin A in mice— E. L. Felix et al.



Medical Definition of pretreatment (Entry 2 of 2)

: occurring in or typical of the period prior to treatment a patient's pretreatment blood pressure


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