shingle
noun [ C ]
US uk/ˈʃɪŋɡl/ usa sign outside the house or office of a doctor, lawyer, or other professional:
A shingle hangs from his mail-box.
hang (out/up) a shingle
to advertise your services or to start a business as a professional :
Several independent advisers have hung a shingle on the internet.
The two lawyers hung out their shingle in Miami in 1987.