Lewis & Short

fīlum, i. n. (also filus, i, m., acc. to Arn. 1, 36 dub., plur. heterocl., fili, Luc. 6, 460) [for figlum, v. figo], a thread of any thing woven (of linen or woolen cloth, a cobweb, etc.).

  1. I. Lit., Varr. L. L. 5, § 113 Müll.; Enn. ap. Non. 116, 6 (Ann. v. 259 ed. Vahl.); Verg. A. 6, 30; Ov. A. A. 3, 445; id. M. 4, 36; Mart. 6, 3, 5; Cels. 7, 16: lumen candelae cujus tempero filum, wick, Juv. 3, 287: tenuia aranei, a web, Lucr. 3, 383: tineae, Ov. M. 15, 372.
    Poet., of the thread of life spun by the Fates: sororum fila trium, Hor. C. 2, 3, 16; Verg. A. 10, 815; Ov. M. 2, 654; id. Tr. 5, 10, 45; Sil. 4, 28; Mart. 10, 5, 10 al.
    Prov.: pendere filo (tenui), to hang by a thread, for to be in great danger: hac noctu filo pendebit Etruria tota, Enn. ap. Macr. S. 1, 4, § 18 (Ann. v. 153 ed. Vahl.): omnia sunt hominum tenui pendentia filo, Ov. P. 4, 3, 35; Val. Max. 6, 4, 1.
      1. 2. In partic., the fillet of wool wound round the upper part of the flamen’s cap, similar to the στέμμα of the Greeks; hence, in gen., a priest’s fillet: APICVLVM, filum, quo flamines velatum apicem gerunt, Paul. ex Fest. p. 23 Müll.: legatus capite velato filo (lanae velamen est), Audi, Juppiter, inquit, etc., Liv. 1, 32, 6: filo velatus, Tib. 1, 5, 15.
    1. B. Transf. (mostly poet. and in post-Aug. prose).
      1. 1. Of any thing slender and drawn out like a thread, a string, cord, filament, fibre: tractat inauratae consona fila lyrae, the strings, Ov. Am. 1, 8, 60; so, lyrae, id. M. 5, 118: sonantia, id. ib. 10, 89: croci, i. e. the stamen, id. F. 1, 342: foliorum exilitas usque in fila attenuata, Plin. 21, 6, 16, § 30; 11, 15, 15, § 39.
      2. 2. Plur., shreds, slices, remnants: fila sectivi porri, Juv. 14, 133: porris fila resecta suis, Mart. 11, 52: fila Tarentini graviter redolentia porri edisti, id. 13, 18.
      3. 3. I. q. crassitudo, the density, compactness, compact shape, or, in gen., contour, form, shape of an object: forma quoque hinc solis debet filumque videri, Lucr. 5, 571, v. Lachm. ad h. 1.; cf. id. 5, 581; 2, 341; 4, 88: mulieris, Plaut. Merc. 4, 4, 15: corporis, Varr. L. L. 10, § 4 Müll.; Gell. 1, 9, 2; Amm. 14, 11, 28: forma atque filo virginali, id. 14, 4, 2: ingeniosus est et bono filo, Petr. 46.
  2. II. Trop. (cf. the preced. no.), of speech, texture, sort, quality, nature, style (class.): ego hospiti veteri et amico munusculum mittere (volui) levidense, crasso filo, cujusmodi ipsius solent esse munera, i. e. of coarse texture, Cic. Fam. 9, 12, 2; cf.: argumentandi tenue filum, id. Or. 36, 124: tenui deducta poëmata filo, Hor. Ep. 2, 1, 225; cf.: gracili connectere carmina filo, Col. poët. 10, 227: paulo uberiore filo, Cic. de Or. 2, 22, 93: orationis, id. ib. 3, 26, 103: aliud quoddam filum orationis tuae (= oratio uberior), id. Lael. 7, 25.