Search Result for "impregnable": 
Wordnet 3.0

ADJECTIVE (3)

1. immune to attack; incapable of being tampered with;
- Example: "an impregnable fortress"
- Example: "fortifications that made the frontier inviolable"
- Example: "a secure telephone connection"
[syn: impregnable, inviolable, secure, strong, unassailable, unattackable]

2. capable of conceiving;
[syn: conceptive, impregnable]

3. incapable of being overcome, challenged or refuted;
- Example: "an impregnable argument"
- Example: "impregnable self-confidence"
[syn: impregnable, inexpugnable]


The Collaborative International Dictionary of English v.0.48:

Impregnable \Im*preg"na*ble\, a. [F. imprenable; pref. im- not + prenable pregnable, fr. prendre to take, L. prehendere. See Comprehend, Get to obtain.] Not to be stormed, or taken by assault; incapable of being subdued; able to resist attack; unconquerable; as, an impregnable fortress; impregnable virtue. [1913 Webster] The man's affection remains wholly unconcerned and impregnable. --South. -- Im*preg"na*ble*ness, n. -- Im*preg"na*bly, adv. [1913 Webster]
The Collaborative International Dictionary of English v.0.48:

Impregnable \Im*preg"na*ble\, a. [See Impregnate.] (Biol.) Capable of being impregnated, as the egg of an animal, or the ovule of a plant. [1913 Webster]
WordNet (r) 3.0 (2006):

impregnable adj 1: immune to attack; incapable of being tampered with; "an impregnable fortress"; "fortifications that made the frontier inviolable"; "a secure telephone connection" [syn: impregnable, inviolable, secure, strong, unassailable, unattackable] 2: capable of conceiving [syn: conceptive, impregnable] 3: incapable of being overcome, challenged or refuted; "an impregnable argument"; "impregnable self-confidence" [syn: impregnable, inexpugnable]
Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "impregnable": deathless, defended, guarded, immortal, impenetrable, imperishable, incontestable, incorruptible, indelible, indestructible, indomitable, ineffaceable, ineradicable, inexpugnable, inextinguishable, insuperable, invincible, inviolable, invulnerable, irresistible, mighty, nonperishable, overpowering, overwhelming, protected, quenchless, resistless, safe, safeguarded, secure, shielded, unassailable, unbeatable, unconquerable, undampable, undefeatable, undestroyable, undying, unquenchable, unsubduable, unsurmountable, unyielding