Impropriety and Venial sin

Impropriety noun - The quality or state of not being socially proper.

Venial sin and impropriety are semantically related In some cases you can use "Venial sin" instead a noun "Impropriety".

Venial sin noun - A pardonable sin regarded as entailing only a partial loss of grace.

Impropriety and venial sin are semantically related in slight transgression topic. You can use "Impropriety" instead a noun phrase "Venial sin".