1. A @[email protected] that forms @[email protected] with organic or inorganic guests, or a chemical species that can accommodate guests within cavities of its crystal structure. Examples include @[email protected] and @[email protected] (where there are ion-dipole attractions between heteroatoms and positive ions), @[email protected] molecules that form '@[email protected]' (e.g. hydroquinone and water), and host molecules of @[email protected] (e.g. urea or thiourea). @[email protected] and @[email protected] bind the @[email protected] to the host molecule in @[email protected] and inclusion compounds.
    PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1122 [Terms] [Paper]
  2. (in biotechnology) A cell whose @[email protected] is used for growth and reproduction of a virus, @[email protected] or other form of foreign @[email protected]
    PAC, 1992, 64, 143. (Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992)) on page 156 [Terms] [Paper]