DCHP-1 Online
tin-cow Esp. West, Slang 
n. See quotes.
- 1889 Some of the old timers feast occasionally on hardtack covered with dopebutter--and in their tea or strong coffee they use the tin-cow--condensed milk.
- 1910 The condensed milk . . . is correctly known as "tin cow."
- 1962 In the commissariat department [are] "dope" (butter) . . . "tin-cow " (condensed milk). . . .
- 1889 Some of the old timers feast occasionally on hardtack covered with dopebutter--and in their tea or strong coffee they use the tin-cow--condensed milk.