messenger

US /ˈmɛsəndʒɚ/

・

UK /ˈmesɪndʒə(r)/

Someone who delivers things, e.g. by motor bike
A computer program or application used for sending and receiving messages online.
A program or application used for sending instant messages.
A person who formerly carried official communications.
A person who carries a message or is employed to carry messages.