Chemical Chemistry A  Adjective Relating B Means Noun

chem·i·cal

I

 \\ˈke-mi-kəl\\ adjective1. of, relating to, used in, or produced by chemistry or the phenomena of chemistry
    chemical reactions
2.
  a. acting or operated or produced by chemicals
      a chemical fire extinguisher
  b. detectable by chemical means
• chem·i·cal·ly  \\-mi-k(ə-)lē\\ adverb

II

noun1. a substance obtained by a chemical process or producing a chemical effect
2. 

drug

 3

chem·i·cal
I. \ˈkemə̇kəl, -ēk-\ adjective
Etymology: alteration of earlier chimical, from chimic (earlier form of chemic) + -al
1. 
 a. obsolete : 
 b. archaic : of or relating to Paracelsian medicine specifically as it opposes Galenic medicine
2. : relating to applications of chemistry: as
 a. : acting or operated by chemical means
  < a chemical extinguisher >
 b. : treated with or performed by the aid of chemicals
  < chemical development in photography >
 c. : produced by chemical means or synthesized from chemicals
  < chemical fiber >
  < chemical rubber >
 d. : suitable for use in or used for operations in chemistry
  < a chemical laboratory >
  < a chemical plant >
3. : having reference to or relating to the science of chemistry: as
 a. : occupied with chemistry
  < a chemical researcher >
  < chemical societies >
 b. : dealing with chemistry
  < a chemical journal >
  < chemical nomenclature >
 c. : characterized by the phenomena of chemistry
  < chemical changes >
  < chemical forces >
4. : of or relating to rocks (as gypsum, salt, and most limestones) that are deposited from solution
II. noun
(-s)
Etymology: alteration of earlier chimical, from chimical, adjective
: a substance (as an acid, alkali, salt, synthetic organic compound) obtained by a chemical process, prepared for use in chemical manufacture, or used for producing a chemical effect — see , 
III. transitive verb
(-ed/-ing/-s)
: