Search Result for "imperceptible": 
Wordnet 3.0

ADJECTIVE (1)

1. impossible or difficult to perceive by the mind or senses;
- Example: "an imperceptible drop in temperature"
- Example: "an imperceptible nod"
- Example: "color is unperceivable to the touch"
[syn: imperceptible, unperceivable]



The Collaborative International Dictionary of English v.0.48:

Imperceptible \Im`per*cep"ti*ble\, a. [Pref. im- not +
   perceptible: cf. F. imperceptible.]
   Not perceptible; not to be apprehended or cognized by the
   senses; not discernible by the mind; not easily apprehended.
   [1913 Webster]

         Almost imperceptible to the touch.       --Dryden.
   [1913 Webster]

         Its operation is slow, and in some cases almost
         imperceptible.                           --Burke.
   -- Im`per*cep"ti*ble*ness, n. -- Im`per*cep"ti*bly, adv.
   [1913 Webster]

         Their . . . subtilty and imperceptibleness. --Sir M.
                                                  Hale.
   [1913 Webster]


WordNet (r) 3.0 (2006):

imperceptible
    adj 1: impossible or difficult to perceive by the mind or
           senses; "an imperceptible drop in temperature"; "an
           imperceptible nod"; "color is unperceivable to the touch"
           [syn: imperceptible, unperceivable] [ant:
           perceptible]