aestus, ūs (archaic gen. aesti, Pac. 97 Rib.; rare form of nom. plur. aestuus). m. [kind. with aestas and Gr. αἴθω; v. aestas], an undulating, boiling, waving, tossing; a waving, heaving, billowy motion.
I Lit.
A Of fire; hence, in gen., fire , glow , heat (orig. in relation to its flashing up; while fervor denotes a glowing, ardor a burning, and calor a warming heat; yet it was early used for warming heat; v. the following example): nam fretus ipse anni permiscet frigus et aestum, heat and cold are blended , Lucr. 6, 364 (for which calor, id. 6, 368, 371 al.): multa aestu victa per agros, id. 5, 1104: exsuperant flammae, furit aestus ad auras, Verg. A. 2, 759: caniculae, Hor. C. 1, 17, 18; so id. Ep. 1, 8, 5: labore et aestu languidus, Sall. J. 51.—In plur.: neque frigora neque aestus facile tolerabat, Suet. Aug. 81.—So of midday heat : aestibus at mediis umbrosam exquirere vallem, Verg. G. 3, 331 (cf. Cic. Ac. 2 Luc.), 22, 70: ille cum aestuaret, umbram secutus est).—And of the heat of disease (of wounds, fever, inflammation, etc.): ulceris aestus, Att. ap. Cic. Tusc. 2, 7, 19: homines aegri cum aestu febrique jactantur, Cic. Cat. 1, 13.—
B The undulating , heaving motion of the sea , the swell , surge : fervet aestu pelagus, Pac. ap. Cic. de Or. 3, 39; hence, meton. for the sea in agitation , waves , billows : delphines aestum secabant, Verg. A. 8, 674: furit aestus harenis, id. ib. 1, 107: aestus totos campos inundaverant, Curt. 9, 9, 18.—In Verg. once of the boiling up of water in a vessel : exsultant aestu latices, Aen. 7, 464.—
C Esp., the periodical flux and reflux or ebb and flow of the sea , the tide (cf. Varr. L. L. 9, 19; Mel. 3, 1: aestus maris accedere et reciprocare maxime mirum, pluribus quidem modis, sed causa in sole lunāque, Plin. 2, 97, 99, 212); Plaut. As. 1, 3, 6: quid de fretis aut de marinis aestibus dicam? quorum accessus et recessus ( flow and ebb ) lunae motu gubernantur, Cic. Div. 2, 14 fin. : crescens, Plin. 2, 100, 97, § 219: decedens, id. ib.: recedens, id. 2, 98, 101, § 220: secundus, in our favor , Sall. Fragm. ap. Gell. 10, 26, 2: adversus, against us , id. ap. Non. 138, 8.—
II Trop.
A The passionate ferment or commotion of the mind , the fire , glow , ardor of any ( even a good ) passion (cf. aestuo, II. A.): et belli magnos commovit funditus aestus (genus humanum), has stirred up from their very bottom the waves of discord , Lucr. 5, 1434: civilis belli aestus, Hor. Ep. 2, 2, 47 (cf. id. C. 2, 7, 15): repente te quasi quidam aestus ingenii tui procul a terrā abripuit atque in altum abstraxit, Cic. de Or. 3, 36: hunc absorbuit aestus quidam gloriae, id. Brut. 81: stultorum regum et populorum continet aestus, Hor. Ep. 1, 2, 8: perstet et, ut pelagi, sic pectoris adjuvet aestum, the glow of love , Ov. H. 16, 25.—
B A vacillating , irresolute state of mind , doubt , uncertainty , hesitation , trouble , embarrassment , anxiely : qui tibi aestus, qui error, quae tenebrae, Cic. Div. in Caecin. 14: vario fluctuat aestu, Verg. A. 12, 486: amor magno irarum fluctuat aestu, id. ib. 4, 532; cf. id. ib. 8, 19: aestus curaeque graves, Hor. S. 1, 2, 110.—
C In the Epicurean philos. lang. of Lucretius, the undulatory flow or stream of atoms , atomic efflux , as the cause of perception (cf. affluo, I.): Perpetuoque fluunt certis ab rebus odores, Frigus ut a fluviis, calor ab sole, aestus ab undis Aequoris, exesor moerorum litora propter, etc., Lucr. 6, 926; and in id. 6, 1002 sq., the magnetic fluid is several times designated by aestus lapidis.