This is the 349th most frequent Japanese word.
電話
Telephone.
Here, 「電話」 (denwa) means a phone as a physical device.
彼は新しい電話を買いました。
He bought a new phone.
In this case, 「電話」 (denwa) refers to the act of making a telephone call.
すぐに電話してください。
Please call me immediately.
Here, 「電話」 (denwa) signifies a phone call received.