Not susceptible to or admitting of: unsusceptible to illegal entry. (adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "unsusceptible" in a sentence
"That out of the sea were born either, no one name unsusceptible."
"Last night we had the unexpected bonus of Trudie Styler popping in to play Mrs Thrale, who charmed the normally unsusceptible hero."
"Can one fix some exquisite entity, as it were, in amber, immune from changing fashion and unsusceptible to the contamination of the whims of the insistent rich?"