Faithful loan are compounds in which the structure of the compound in the spoken language and the structure of the compound in the sign language is identical.
An example of faithful loan is the sign fish^sword, ‘swordfish’ (Ita. pescespada).
fish^sword
‘Swordfish’ (based on Santoro, 2018: 68)
The first member is the core sign fish, and the second member is the core sign sword, which is articulated on the nose on the signer. Here there is a one-to-one relation with the Italian compound, which is composed by pesce, ‘fish’, and spada, ‘sword’, just like in LIS.