| less important |
| impalpable(adjective, knowledge, heavenly, subtle, imperceptible) |
| intangible(adjective, light, knowledge, heavenly, indefinite) |
| immaterial(adjective, form, light, weak, negative) |
| ethereal(adjective, negative, heavenly, imperceptible, levity) |
| imperceptible(adjective, hard, knowledge, faint) |
| insensible(adjective, knowledge, heavenly, subtle, imperceptible) |
| invisible(adjective, knowledge, hidden, unable, imperceptible) |
| airy(adjective, light, negative, heavenly, levity) |
| elusive(adjective, vague, impulsive, unpredictable, mysterious) |
| inappreciable(adjective, knowledge, imperceptible) |
| incorporeal(adjective, light, weak, slight, heavenly) |
| insubstantial(adjective, light, weak, slight, negative) |
| shadowy(adjective, negative, heavenly, imperceptible, vacant) |
| subtle(adjective, vague, unpredictable, mysterious, ambiguous) |
| unobservable(adjective, knowledge, imperceptible) |
| unsubstantial(adjective, light, weak, slight, heavenly) |
| bodiless(adjective, heavenly, immaterial, incorporeal, nonmaterial) |
| evanescent(adjective, imperceptible) |
| indiscernible(adjective, knowledge, imperceptible) |