imperceptible
im.per.cep.ti.ble \.im-p*r-'sep-t*-b*l\ \-ble-\ aj [MF, fr. ML imperceptibilis, fr. L in- + LL perceptibilis per]ceptible : not perceptible by a sense or by the mind : extremely slight, gradual , or subtle - im.per.cep.ti.bly av
im.per.cep.ti.ble \.im-p*r-'sep-t*-b*l\ \-ble-\ aj [MF, fr. ML imperceptibilis, fr. L in- + LL perceptibilis per]ceptible : not perceptible by a sense or by the mind : extremely slight, gradual , or subtle - im.per.cep.ti.bly av