1. in a way that does not allow something to pass through or penetrate
2. in a way that is not affected or influenced by something

Examples

• The raincoat was designed imperviously to keep water out.
• She walked imperviously through the crowd, ignoring all the noise.
• The material sealed imperviously against moisture.
• He continued imperviously with his work despite the criticism.
• The barrier stood imperviously against the wind and rain.
• She remained imperviously calm during the heated argument.