The Collaborative International Dictionary of English v.0.48:
Methenyl \Meth"e*nyl\, n. [Methene + -yl.] (Chem.)
   The hypothetical hydrocarbon radical CH, regarded as an
   essential residue of certain organic compounds.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Tetrazine \Tet*raz"ine\, n. Also -in \-in\ . [Tetrazo- + -ine.]
   (Chem.)
   A hypothetical compound, C2H2N4 which may be regarded as
   benzene with four CH groups replaced by nitrogen atoms;
   also, any of various derivatives of the same. There are three
   isomeric varieties.
   [Webster 1913 Suppl.]
The Collaborative International Dictionary of English v.0.48:
Tetrazole \Tet*raz"ole\, n. [Tetrazo- + -ole.] (Org. Chem.)
   A crystalline acid substance, CH2N4, which may be regarded
   as pyrrol in which nitrogen atoms replace three CH groups;
   also, any of various derivatives of the same.
   [Webster 1913 Suppl.]
The Collaborative International Dictionary of English v.0.48:
Azole \Az"ole\, n. [From Azote.] (Org. Chem.)
   Any of a large class of compounds characterized by a
   five-membered ring which contains an atom of nitrogen and at
   least one other noncarbon atom (nitrogen, oxygen, sulphur).
   The prefixes furo-, thio, and pyrro- are used to distinguish
   three subclasses of azoles, which may be regarded as derived
   respectively from furfuran, thiophene, and pyrrol by
   replacement of the CH group by nitrogen; as, furo-monazole.
   Names exactly analogous to those for the azines are also
   used; as, oxazole, diazole, etc.
   [Webster 1913 Suppl.]
The Free On-line Dictionary of Computing (30 December 2018):
Ch
    An interpreted programming language sold by Soft
   Integration and marketed for scripting, shell programming
   and graph plotting, it is a superset of C++.  Ch is also the
   name of Soft Integration's interpreter for the language.
   Currently the Ch interpreter is available for Windows,
   Solaris, HP-UX, Linux and Mac platforms.
   Soft Integration (http://softintegration.com/).
   (2003-08-15)
The Free On-line Dictionary of Computing (30 December 2018):
ch
    The country code for Switzerland.
   (1999-01-27)