When you look up RCD in Leo you find this entry:
residual-current-operated protective device [abbr.: RCD]
RCD (residual current device) is the familiar generic term. There are specific types, which need to be distinguished.
The terms RCCB and RCD look similar, but you can add the full definition:
RCCB = Residual Current Operated Circuit-Breaker without Integral Overcurrent Protection.
Then this is distinguished from an RCBO, which is an RCD with overcurrent protection.
Both act as circuit breakers.
An RCD is used instead of the old type of fuse (the type with the melting wire), and offers extra protection.
Here is a list of the types of RCD:
• RCCB (Residual Current Operated Circuit-Breaker without Integral Overcurrent Protection)
• RCBO (Residual Current Operated Circuit-Breaker with Integral Overcurrent Protection)
• SRCD (Socket-Outlet incorporating a Residual Current Device)
• FCURCD (Fused Connection Unit incorporating a Residual Current Device)
• PRCD (Portable Residual Current Device)
• CBR (Circuit-Breaker incorporating Residual Current Protection)
• RCM (Residual Current Monitor)
• MRCD (Modular Residual Current Device)
As a general term, "residual-current circuit breaker" is clear and descriptive.