noun or participle which takes 'suru'
A telephone service that notifies you of an incoming call while you are already on a call, allowing you to switch between calls.
割込通話を利用すると、通話中に別の着信に応答できます。
By using call waiting, you can answer another incoming call while on a call.
キャッチホン is a common wasei-eigo term for call waiting, often used in everyday conversation, while 割込通話 is a more formal or technical term.
Compound of 割込 (わりこみ, 'interruption') and 通話 (つうわ, 'telephone call'), literally 'interrupting call'.