Hassock

[Hina Muqadas]

A small stuffed cushion or footstool, for kneeling on in
church, or for home use.

[Becky]

A cushion for kneeling on in church, while at prayer.

[Tracie Lynn]

[Litterally] a [prayer] [cushion], however sounds like one of the most fantastic insults imagineable. Used to insult god-fanatics and all manner of church-goers in order to remove their one decently named material possession.

[Monty]

An upholstered footstool or ottoman.