I. ˈadəd.iv, -ətiv adjective
Etymology: Late Latin additivus, from Latin additus (past participle of addere to add) + -ivus -ive — more at add
1. : tending to add or be added : admitting, involving, or characterized by addition
the process of cultural development is … additive — A.L.Kroeber
2. philosophy : having the distinctive character of extensive magnitudes : of the nature of an addition or aggregation rather than an organic union of parts
this pluralistic view of a world of additive constitution — William James
3. : having a numeral value equal to the sum of the values for the component parts — used of a property; compare colligative , constitutive 3
molecular weight may be thought of as an additive property
4. : relating to the sum of the pharmacological responses produced by the concurrent administration of two or more drugs capable of producing the same kind of effect
5.
a. : relating to the controlled mixing of colored light sources (as red, green, and blue) to form a colored image : formed by superposition or other nondestructive combination of colored lights
b. : relating to a method of making halftone color prints in which the dots for each color are placed beside each other
6. : having a genic effect that is the sum of the individual effects
• ad·di·tive·ly adverb
II. noun
( -s )
1. : a substance added to another in relatively small amounts to impart or improve desirable properties or suppress undesirable properties: as
a. : a chemical added to a lubricating oil to make it suitable for use at extreme pressures or to prevent corrosion
an extreme-pressure additive
b. : a chemical (as an antiknock agent or an agent for counteracting deposits on spark plugs) added to gasoline
tetraethyl lead is a gasoline additive
c. : an agent added to a foodstuff to improve color, flavor, texture, or keeping qualities
gelatin is an additive in the manufacture of ice cream
d. : material added to soil or feeds to improve plant or animal growth by indirect action
2. : an arithmetical key for superencipherment especially when numeral code groups are enciphered by adding to them a numeral keying sequence usually by noncarrying addition