(a.) Not appreciable; too small to be perceived; incapable of being duly valued or estimated.

atomic back-burner corpuscular dinky dispensable embryonic evanescent germinal granular immaterial impalpable imperceptible imponderable inadequate inconsequential inconsiderable indiscernible inessential inferior infinitesimal insensible insignificant insufficient intangible invisible irrelevant little microcosmic microscopic minor minute molecular negligible nonessential not vital petit scanty scrimpy skimpy small subatomic technical tenuous thin ultramicroscopic unapparent unappreciable unessential unimpressive unnoteworthy unobservable unperceivable unseeable