Too slight, gradual, fleeting, subtle, minute, or indistinct to be perceptible to the mind or senses; hardly discernible.

Incapable of being observed; not noticeable.

Imperceptible; incapable of being observed or noted. Cf. remarkable, adj. 2a. Obsolete. rare.

Not evident, not manifest; lacking evidence; not clear or obvious, obscure.

Unable to be observed; imperceptible, unnoticeable.

Of a movement or physical action: small, delicate; inconspicuous, unpronounced.

Too small to be discerned; imperceptible.

Not easily noticed or observed; that cannot be noticed or detected.

Not readily seen or noticed; not prominent or striking in appearance or character.

Not noticeable, prominent, or distinct; inconspicuous.

(un-, prefix1 affix 1b.)

(un-, prefix1 affix 1.)

(un-, prefix1 affix 1.)

Unapparent. rare.