Lewis & Short

mĕrum, i, n., v. merus, 2.

mĕrus, a, um, adj. [root mar-, to gleam; cf.: μάρμαρος, marmor, mare; hence, bright, pure], pure, unmixed, unadulterated, esp. of wine not mixed with water: merum antiqui dicebant solum: at nunc merum purum appellamus, Paul. ex Fest. p. 124 Müll.

  1. I. Lit.: vinum merum, Varr. ap. Non. 4, 295: vina, Ov. M. 15, 331.
    Of other things: argentum merum, Plaut. As. 1, 3, 3: undae, Ov. M. 15, 323: lac, id. F. 4, 369: gustus, Col. 3, 21: claror, clear, unclouded, Plaut. Most. 3, 1, 111: mero meridie, Petr. 37.
    Hence,
      1. 2. Subst.: mĕrum, i, n., pure, unmixed wine, wine not mixed with water (poet. and in post-Aug. prose): ingurgitare se in merum, Plaut. Curc. 1, 2, 35; Hor. Ep. 1, 19, 11; id. C. 1, 36, 13: objecturus Antonio Cicero merum et vomitum, Quint. 8, 4, 16: meri veteris torrens, Juv. 6, 319; 3, 283; Val. Fl. 5, 595: ad merum pronior, Plin. 14, 22, 28, § 145; 23, 1, 23, § 43.
    1. B. Transf.
      1. 1. Bare, naked, uncovered (poet.): pes, Juv. 6, 158: stabat calce merā, Prud. στεφ. 6, 91.
      2. 2. In gen., bare, nothing but, only, mere (class.): meri bellatores gignuntur, Plaut. Mil. 4, 2, 85: in medio (foro) ostentatores meri (ambulant), id. Curc. 4, 1, 15: Diogenem postea pallium solum habuisse, et habere Ulixem meram tunicam, nothing but, only, Varr. ap. Non. 344, 10: nihil, nisi spem meram, Ter. Phorm. 1, 2, 95: mera monstra nuntiare, Cic. Att. 4, 7, 1: proscriptiones, meri Sullae, id. ib. 9, 11, 3: scelera loquuntur, id. ib. 9, 13, 1: bellum, id. ib. 9, 13, 8: nugae, id. ib. 6, 3, 5: adfectus, Quint. 11, 1, 52.
  2. II. Trop., pure, true, real, genuine, unadulterated: meri principes, Cic. de Or. 2, 22, 94: velut ex diutinā siti nimis avide meram haurientes libertatem, immoderate, excessive, Liv. 39, 26; cf. Cic. Rep. 1, 43, 66; but mera libertas, in Horace, signifies true, genuine freedom, Hor. Ep. 1, 18, 8: Achaia, illa vera et mera Graecia, Plin. Ep. 8, 24, 2: Cecropis, a real Athenian, Juv. 6, 187.
    Hence, adv.: mĕrē, purely, without mixture, wholly, entirely (ante-class. and post-Aug.): si semel amoris poculum accepit mere, Plaut. Truc. 1, 1, 22.