1) Building block 2) Unit 3) Within the molecule 1) Inner 
• (a.) Between molecules; situated, or acting, between the molecules of bodies.
(1) Descriptive of any process that involves a transfer (of atoms, groups, electrons, etc.) or interactions between different parts of the same molecular entity. (2) Relating to a comparison between atoms or groups within the same molecular entity. See also intermolecular.
Refers to a characteristic within one molecule or ion, referring only to the atoms in the molecular or ion.
In`tra·mo·lec'u·lar adjective (Chem. & Physics) Between molecules; situated, or acting, between the molecules of bodies. 
Type: Term Pronunciation: in′tră-mŏ-lek′yū-lăr Definitions: 1. Referring to situations and events within a molecule.
[adj] - within the molecule
adjective within the molecule; occurring by a reaction between different parts of the same molecule
existing or occurring within a molecule.