1) Inactive 2) Indifferent 3) Inert 4) Neutral 5) Noble 6) Stable 1) Inactive 2) Inert 3) Insensitive 
Failing to react with a specified chemical species under specified conditions. The term should not be used in place of stable, since a relatively more stable species may nevertheless be more reactive than some reference species towards a given reaction partner.
[adj] - not tending to react to stimulation 2. [adj] - (chemistry and physics) not reacting chemically
adjective not tending to react to stimulation