I. ə̇nˈjekshən noun
( -s )
Etymology: Middle French or Latin; Middle French, from Latin injection-, injectio, from injectus + -ion-, -io -ion
1.
a.
(1) : the act or an instance of injecting a drug or other substance into the body
(2) : a solution of a drug, nutrient, or other substance injected (as by catheter or needle) into the tissues, a vein, or a body cavity
(3) : a solution or suspension of a drug intended for administration under or through the skin or mucous membranes by means of a hypodermic syringe
(4) : an act or process of injecting vessels or tissues ; also : a specimen prepared by injection — compare corrosion
(5) : the state of being injected : congestion
b. : the intrusion of molten magma between rocks
c. : the introduction under pressure of one substance (as fuel oil, combustion air, or water spray) into a working space (as a diesel cylinder, a gas-turbine combustor, or a steam desuperheater)
2. : the act or an instance of introducing some element or factor into a situation or subject
injection into news reports of the editor's political prejudices — Martin Gardner
II. noun
1.
a. : the placing of an artificial satellite or a spacecraft into an orbit or on a trajectory — called also insertion
b. : the time or place at which injection occurs
2. : a mathematical function that is a one-to-one mapping — compare bijection herein surjection herein