Green’s Dictionary of Slang

(US) drunk.

1900		E.H. Babbitt ‘College Words and Phrases’ in DN II:i 48: piffed, adj. Intoxicated.
1907		Fairmount W. Virginian (VA) 20 May 2/6: In th afternoon he became so bady ‘piffed’ that he could scarcely walk.
1912		Univ. Missourian (Columbia, MO) 11 Apr. 5/3: Poore was not piffed, but she used the wrong end of the bat.
1921		Aberdeen Wkly (MS) 24 June 7/5: [caption] Piffed Passenger (waving wildly to conductor) ‘Say...’.
1929		M. Prenner ‘More Sl. Words for “Drunk”’ in AS IV:6 441: piffed, piffled, pifflicated.
1931		A. Hardin ‘Volstead Eng.’ in AS VII:2 88: Terms referring to the state of intoxication: [...] Verbs: Piffed. Piffled.