addition

https://doi.org/10.1351/goldbook.A00132
  1. Refers to
    addition reaction
    or addition
    transformation
    .
  2. Loosely, the formation of an
    adduct
    . (For an example, see
    Lewis acid
    .)
  3. Loosely, any
    association
    or
    attachment
    .
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1081 [Terms] [Paper]