INSENTIENT
insentient, insensate
(adjective) devoid of feeling and consciousness and animation; “insentient (or insensate) stone”
Source: WordNet® 3.1
Etymology
Adjective
insentient (comparative more insentient, superlative most insentient)
having no consciousness or animation; not sentient
Insensitive, indifferent
Source: Wiktionary
In*sen"ti*ent, a.
Definition: Not sentient; not having perception, or the power of
perception.
The . . . attributes of an insentient, inert substance. Reid.
But there can be nothing like to this sensation in the rose, because
it is insentient. Sir W. Hamilton.
Source: Webster’s Unabridged Dictionary 1913 Edition