1. the part of a telephone that you hold in your hand, containing the earpiece and mouthpiece
Usage: common in everyday use; often used with landline phones
2. a mobile phone or cellular phone
Usage: informal; modern usage

Examples

• She picked up the handset and dialed the number.
• The old telephone had a heavy black handset.
• He put the handset back on the cradle after the call ended.
• Modern handsets are much more advanced than phones from twenty years ago.
• The handset felt warm against her ear after the long conversation.
• I need to replace the handset on my desk phone because it's broken.