Search Result for "impenetrable": 
Wordnet 3.0

ADJECTIVE (3)

1. not admitting of penetration or passage into or through;
- Example: "an impenetrable fortress"
- Example: "impenetrable rain forests"

2. permitting little if any light to pass through because of denseness of matter;
- Example: "dense smoke"
- Example: "heavy fog"
- Example: "impenetrable gloom"
[syn: dense, heavy, impenetrable]

3. impossible to understand;
- Example: "impenetrable jargon"



The Collaborative International Dictionary of English v.0.48:

Impenetrable \Im*pen"e*tra*ble\, a. [L. impenetrabilis; pref.
   im- not + penetrabilis penetrable: cf. F.
   imp['e]n['e]trable.]
   1. Incapable of being penetrated or pierced; not admitting
      the passage of other bodies; not to be entered;
      impervious; as, an impenetrable shield.
      [1913 Webster]

            Highest woods impenetrable
            To star or sunlight.                  --Milton.
      [1913 Webster]

   2. (Physics) Having the property of preventing any other
      substance from occupying the same space at the same time.
      [1913 Webster]

   3. Inaccessible, as to knowledge, reason, sympathy, etc.;
      unimpressible; not to be moved by arguments or motives;
      as, an impenetrable mind, or heart.
      [1913 Webster]

            They will be credulous in all affairs of life, but
            impenetrable by a sermon of the gospel. --Jer.
                                                  Taylor.
      [1913 Webster]


WordNet (r) 3.0 (2006):

impenetrable
    adj 1: not admitting of penetration or passage into or through;
           "an impenetrable fortress"; "impenetrable rain forests"
           [ant: penetrable]
    2: permitting little if any light to pass through because of
       denseness of matter; "dense smoke"; "heavy fog";
       "impenetrable gloom" [syn: dense, heavy, impenetrable]
    3: impossible to understand; "impenetrable jargon"