Noun
frottoir (plural frottoirs)
Synonym of rubboard
A frottoir is played with a stroking instrument (usually with spoon handles or a pair of bottle-openers) in each hand. Source: Internet
In Zydeco bands, the frottoir is usually played with bottle openers, to make a louder sound. Source: Internet
Conversely, the frottoir (zydeco rubboard) dispenses with the frame and consists simply of the metal ribbing hung around the neck. Source: Internet
In a 4-beat measure, the frottoir will be stroked 8 to 16 times. Source: Internet