inalienable
indefeasible
indefinable
indescribable
ineffable
inenarrable
inexpressible
innominable
noncommunicable
noncontagious
noninfectious
undefinable
unimpartable
unmentionable
unnameable
unspeakable
unutterable
unwhisperable
incommunicability
God-given
birthday/holiday/no-reason-whatsoever
enviable
feety
immedicable
imponderable
insolvable
intangible
irremediable
knick
monocultural
self-renouncing
supersensuous
transcendent
unattainable
undefined
undying
unequaled
unliterary
unrepeatable
untranslatable
communicable