29 C.F.R. § 779.23

As used in the Act, the term establishment, which is not specially defined therein, refers to a “distinct physical place of business” rather than to “an entire business or enterprise” which may include several separate places of business. This is consistent with the meaning of the term as it is normally used in business and in government, is judicially settled, and has been recognized in the Congress in the course of enactment of amendatory legislation (Phillips v. Walling, 324 U.S. 490; Mitchell v. Bekins Van & Storage Co., 352 U.S. 1027; 95 Cong. Rec. 12505, 12579, 14877; H. Rept. No. 1453, 81st Cong., 1st Sess., p. 25). As appears more fully elsewhere in this part, this is the meaning of the term as used in sections 3(r), 3(s), 6(d), 7(i), 13(a), 13(b), and 14 of the Act.