1. 不尊敬的：impingement 侵犯 | impious 不尊敬的 | impiously 不信神地

2. 不虔敬的：impetuous#猛烈的;鲁莽的 | impious#不虔敬的 | impromptu#临时的

3. 无信仰的, 不虔诚的, 不敬神的 (形)：impingement 影响 (名) | impious 无信仰的, 不虔诚的, 不敬神的 (形) | impiously 不信神地; 不虔诚地 (副)

1. 不虔诚的;不敬神的;不敬的
If you describe someone as impious, you mean that they show a lack of respect for religious things.

adj

1. lacking piety or reverence for a god

2. lacking due respect or dutifulness

e.g. impious toward one's parents
an undutiful son

Synonym: undutiful