Lewis & Short

Argīlētum, i, n. [Argiletum sunt qui scripserunt ab Argolā, seu quod is huc venerit ibique sit sepultus; alii ab argillā, quod ibi id genus terrae, Varr. L. L. 5, § 157 Müll.: sane Argiletum quasi Argilletum multi volunt a pingui terrā, Serv. ad Verg. A. 8, 345; cf. Spald. ad Quint. 1, 6, 31], a part of Rome, in the Vicus Tuscus, between the Circus Maximus and Mons Aventinus, where handicraftsmen and booksellers traded, Cic. Att. 12, 32; Verg. A. 8, 345.
Also, acc. to the first explanation of the word, separated (per tmesin): Argique letum, Mart. 2, 17, 3; 1, 118, 9.
Hence, Argīlētānus, a, um, adj., of or belonging to the place Argiletum: aedificium, standing upon the Argiletum, Cic. Att. 1, 14 fin.: tabernae, Mart. 1, 4 (cf. Hor. Ep. 1. 20, 1).