Lewis & Short

pĕrennis (‡ pĕremnis, Inscr. Ann. p. Chr. 341 ap. Guattani Monum. Inedit. 1, 5, p. 39), e

    (
  1. I. abl. sing. perenne, Ov. H. 8, 64; id. F. 3, 654), adj. [per-annus], that lasts or continues the year through (post-Aug.): aves perennes, that remain with us all the year round, Plin. 10, 25, 36, § 73.
  2. II. Transf., everlasting, never failing, unceasing, perpetual, perennial (class.; cf.: jugis, perpetuus): aquae, Cic. Verr. 2, 4, 48, § 107; cf. Liv. 1, 21, 3: fons, Caes. B. G. 8, 43: amnis, Liv. 4, 30: rivi, Plin. Ep. 5, 6, 11: cursus stellarum, Cic. N. D. 2, 21, 56: vinum, i. e. that bears keeping, Col. 3, 2, 10: adamas, Ov. M. 15, 813: monumenta, id. F. 2, 265; of a person: super Astra ferar, id. M. 15, 875.
    Comp.: exegi monumentum aere perennius, more lasting, more enduring, Hor. C. 3, 30, 1.
    1. B. Trop., unfailing, uninterrupted, continual, perpetual, etc.: lucrum, Plaut. Am. p. 16: perennis et contestata majorum virtus, Cic. Fl. 11, 25: continuata motio et perennis, id. Tusc. 1, 10, 22: loquacitas, id. de Or. 3, 48, 185: animus in rem publicam, id. Prov. Cons. 9, 23.
      Hence, adv., in two forms, pĕrenne (post-Aug.) and pĕrennĭter (post-class.).
    1. A. pĕrenne.
      1. 1. Lit., all the year through, Col. 12, 18, 2.
      2. 2. Transf., constantly, perpetually (postclass.): abies perenne durabilis, Pall. 12, 15, 1: perenne vivax, Paul. Nol. Carm. 11, 68.
    2. B. pĕrennĭter, constantly, continually, always, perpetually: arbor frondens perenniter, Aug. Doctr. Christ. 2, 16: perenniter servare amicitias, Sid. Ep. 7, 9; Cod. Th. 7, 20, 2; Sol. 65.