Origin: Greek suffix -phone
Speakerphone has 2 different meanings across 1 category:
a telephone with a microphone and loudspeaker; can be used without picking up a handset; several people can participate in a call at the same time
"I pressed the speakerphone button so my entire team could join the conference call from their own desks."
A telephone with a microphone and loudspeaker separate from those in the handset.
"I have to put my phone on speakerphone so I can answer the call without holding it up to my ear while driving."