solemn low five
The act of quietly and calmly low fiving others when a location or event does not permit for a loud and/or enthusiastic high five (e.g., a funeral, a library, church, class).
Barney: High five!
Ted: Dude, we're at a wake.
Barney: Sorry. (whispers) Solemn low five.
Ted: Dude, we're at a wake.
Barney: Sorry. (whispers) Solemn low five.