Green’s Dictionary of Slang

buffer n.3

also buffa
[Fr. bouffard, a fool or clown]

1. [early 19C+] a genial old fool, a description more affectionate than critical; thus often as old buffer.

2. [mid-18C+] an eccentric, a fool, used with a degree of contempt.

3. [late 18C–early 19C] an inn-keeper.

4. [mid-19C] a tradesman.

5. [late 19C] as a term of address.