firmāmentum (noun N) : id.
* A strengthening, support, prop (class.; esp. freq. in the trop. sense and in Cic.).
* Lit.: transversaria tigna iniciuntur, quae firmamento esse possint,Caes. B. C. 2, 15, 2: ossa nervique et articuli, firmamenta totius corporis, Sen. de Ira, 2, 1, 2: vincula et firmamenta membrorum,Gell. 13, 22, 9.
* Transf., the sky fixed above the earth, the firmament (late Lat.), Tert. Bapt. 3; Aug. de Genes. ad lit. 2 et saep.
* Trop.
* In gen., a support, prop, stay: eum ordinem, qui exercet vectigalia, firmamentum ceterorum ordinum recte esse dicemus,Cic. de Imp. Pomp. 7, 17: firmamentum ac robur totius accusationis,id. Mur. 28, 58; cf.: multo plus firmamenti ac roboris,id. de Imp. Pomp. 4, 10: parum firmamenti et parum virium,id. Clu. 2, 5: rei publicae,id. Planc. 9, 23; cf.: imperii populi Romani,id. Phil. 3, 5, 13: stabilitatis constantiaeque fides est,id. Lael. 18, 65: dignitatis,id. Tusc. 4, 3, 7: honor sacerdotii firmamentum, potentiae adsumebatur,Tac. H. 5, 8: si ullum firmamentum in illo teste posuisses,Cic. Fl. 37, 92: legionem ex subsidiis in primam aciem firmamentum ducit,as a support,Liv. 29, 2, 9.—In plur.: Romulus cum haec egregia duo firmamenta rei publicae peperisset, auspicia et senatum,Cic. Rep. 2, 10.
* In partic., rhet. t. t., the chief support of an argument, the main point, τὸ συνέχον, Cic. Inv. 1, 14, 19; id. Part. 29, 103; Auct. Her. 1, 16, 26; Quint. 3, 11, 1; 9; 12 sq.

s. TLL