unobservable
ADJECTIVE
imperceptible
Synonyms
WEAK
ephemeral
evanescent
fine
gradual
impalpable
imponderable
inappreciable
inaudible
inconsiderable
inconspicuous
indiscernible
indistinct
indistinguishable
infinitesimal
insensible
insignificant
intangible
invisible
microscopic
minute
momentary
shadowy
slight
small
subtle
tiny
trivial
undetectable
unnoticeable
vague
From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.
