Quiz: Remember the definition of mal de mer?
c.1300, "fact or condition of thriving," also "prosperity, savings," from Middle English thriven "to thrive" (see thrive), possibly influenced by Old Norse þrift, variant of þrif "prosperity," from þrifask "to thrive." Sense of "habit of saving, economy" first recorded 1550s (thrifty in this sense is recorded from 1520s; also see spendthrift). Thrift shop attested by 1919.
Enough to eat; an acceptable standard of living: He isn't rich, but he gets his three squares every day/ homeless men do break the law to get ''three hots and a cot'' (1899+)