impregnable
adjective
1. immune to attack; incapable of being tampered with
- an impregnable fortress
Similar word(s): invulnerable, inviolable, secure, strong, unassailable, unattackable
2. capable of conceiving
Similar word(s): fertile, conceptive
3. incapable of being overcome, challenged or refuted
- an impregnable argument
- impregnable self-confidence
Similar word(s): unconquerable, inexpugnable
Sentences with impregnable as an adjective:
- Following treatment, twenty percent of previously infertile females were impregnable.Application of the compound rendered the non-porous surface impregnable.