The term 'telephone attachment' can be summarized as a device that is connected to a telephone, typically by a CORD. The crossword solution for this term is 'CORD, ' which is an abbreviation of the word 'corded.' Corded telephone attachments are devices that are connected to a telephone via a physical CORD, such as a headset or a speakerphone. These attachments allow users to make and receive calls without having to hold the phone in their hands. They also provide additional features, such as noise cancellation and improved sound quality.