1. Not penetrated.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• ynpierced,
• hnpierced,
• jnpierced,
• inpierced,
• 8npierced,
• 7npierced,
• ubpierced,
• umpierced,
• ujpierced,
• uhpierced,
• unoierced,
• unlierced,
• un-ierced,
• un0ierced,
• unperced,
• unpieced,
• unpiercd,
• Unpersed,
• Unpercied,
• Unpircied

• unfertile,
• unforceful,
• universe,
• unbraced,
• unversed,
• unfriendly,
• unperformed,
• unperceptive,
• unperturbed,
• unpermed,
• unperplexed,
• unfermented,
• unverified,
• unpriced,
• unforced,
• unfirm,
• unperceived.

The adjective form of "unpierced" is "unpierced".

The plural form of the word "unpierced" is still "unpierced." The word does not change in its plural form.

The singular form of the word "unpierced" is "unpierced". The word does not change to a different form when used in singular or plural contexts.