Green’s Dictionary of Slang

1. a prostitute.

1890–1904

Farmer & Henley Sl. and Its Analogues.

2. (US, also toofah, two-for) a cheap cigar; also as adj. (cf. two-for-a-nickel under two adj.).

1892		Chicago Trib. 5 Apr. 4/5: I have shaked 1356 dirty hands today, distributed thirty-six boxes of two-fer cigars, [...] kissed twenty-seven babies [...] [DA].
1907		Quad City Times (Davenport, IA) 17 Nov. 9/1: Then he emulates a donkey / As he puffs a two-fer punkey.
1913		Van Loan ‘For Revenue Only’ in Lucky Seventh (2004) 208: Other merchants [...] offered boxes of cigars – some of them real ‘two-fors.’.
1922		S. Lewis Babbitt (1974) 55: That’s a good two-for.
1923		Wodehouse Inimitable Jeeves 124: Lying on the bed [...] smoking a toofah.
1931		K.C. Times 31 Oct. n.p.: Now the two-fer cigar is with us [DA].

3. (US) a theatre ticket sold at half price, or similar offer; a sandwich man sells such tickets.

1948		Musical America 1 Nov. 11: Two-for-ones, or ‘twofers,’ in theatre jargon, are pairs of tickets sold at the box-office price of a single seat.
1957		J. Blake letter 26 Dec. in Joint (1972) 110: We had a good house that night, having taken the precaution of spreading the rumour that the Chaplain was giving a Christmas gift to every pilgrim who attended. (The shut-in version of twofers).
1964		E. Wilson Earl Wilson’s N.Y. 29: Twofers – Device to purchase a stage-show ticket at half price, ‘twofer one.’.

4. anything sold at a discount of two for the price of one.

1984		J. Ellroy Because the Night 30: [of liquor] Jackie D.'s [...] was almost deserted. [...]. The bartender slipped a napkin in front of him and explained why: ‘Twofers at First Avenue West. Every Tuesday night I get killed’.
2009		L. Tye Satchel 63: The Crawford’s owner gave the public and press a twofer—Josh and Satch—billing them as the ‘greatest battery in history’.