a. [f. L. vacu-us empty, void, free, clear, etc. (cf. VACUUM) + -OUS.]
† 1. Not properly filled out or developed. Obs.–1
1651. Smallwood, Commend. Verses to W. Cartwright’s Wks. False Vacuous Births in every street we see: But seldome, true and ripen’d, such as He.
2. Empty of matter; not occupied or filled with anything solid or tangible.
1655–60. Stanley, Hist. Philos. (1687), 374/1. It were impossible for one body to make another to recede, if the triple dimension … were vacuous.
1677. Gale, Crt. Gentiles, IV. 226. Wil they say that these Atomes were introduced or produced in this vacuous space in time?
1794. R. J. Sulivan, View Nat., IV. 3. He contended, that thunder or sound would not be able to pass through walls,… unless there were some vacuous spaces in those bodies.
1813. T. Busby, Lucretius, II. VI. Comm. p. xxiii. He notices many natural circumstances which … demonstrate the vacuous natures of all substances.
1860. Tyndall, Glac., II. xxiv. 356. The water … is not able to fill it, hence a vacuous space must be formed in the cell.
b. Empty of air or gas; in which a vacuum has been produced.
1669. Boyle, Contin. New Exp., II. (1682), 158. I put Pears bruised into a vacuous Reciever.
1842. E. A. Parnell, Chem. Anal. (1845), 490. The difference between its weight when containing the gas, and when vacuous.
1862. Grove, Corr. Phys. Forces (ed. 2), 59. No air is given off from the bubbles, so they seem to be vacuous.
1892. Photogr. Ann., II. 233. In incandescent lamps the electric current heats up a carbon filament inclosed in a vacuous globe.
c. Bot. Not containing some part or feature usually present.
1866. Treas. Bot., 1199/2. Bracts which usually support flowers are said to be vacuous when they have no flower in their axils.
d. Empty of any visible object.
1877. Morley, Crit. Misc., Ser. II. 255. As the flies of a summer day dart from point to point in the vacuous air.
3. Empty of ideas; unintelligent; expressionless. Cf. VACANT a. 5.
1848. Thackeray, Bk. Snobs, x. A vacuous, solemn … Snob.
1883. Standard, 2 Jan., 5/2. The absence of anxiety … leaves their minds vacuous.
1889. Times, 26 Oct., 9/1. That gift of oppressive familiarity which by some vacuous people is taken to indicate the presence of sterling sense and political aptitude.
Comb. 1895. ‘H. S. Merriman,’ Grey Lady, I. iii. (1899), 28. He was rather a vacuous-looking young man.
b. Indicative of mental vacancy.
1855. Thackeray, Newcomes, II. 25. With that vacuous leer which distinguishes his lordship.
1858. O. W. Holmes, Aut. Breakf.-t., vi. 55. These negative faces with their vacuous eyes and stony lineaments.
1873. Black, Pr. Thule, xx. 320. There was a cheery, vacuous, smiling expression on his round face.
Comb. 1879. McCarthy, Own Times, v. I. 116. A huge white-headed, vacuous-eyed man was to be seen.
4. Devoid of content or substance.
1870. Swinburne, Ess. & Stud. (1875), 56. The vacuous monotonous desire and discontent, the fitful and febrile beauty of Alfred de Musset.
1879. Howells, L. Aroostook (1883), I. 45. Mrs. Erwin wrote an epistolary style exasperatingly vacuous and diffuse.
5. Unoccupied, idle, indolent; not filled up with any (profitable) employment or activity.
1872. Morley, Voltaire, 334. It cannot for ever be tolerable that the mass should wear away their lives in unbroken toil without hope or aim, in order that the few may live selfish and vacuous days.
1897. Review of Rev., 37. There are many rich people who … lead such mean and vacuous lives.
Hence Vacuously adv.; Vacuousness.
1648. W. Mountague, Devout Ess., I. 352. In that vacuousness the winds and vapors of tediousness and displicence rise.
1816. J. Gilchrist, Philos. Etym., 226. The mistiness and vacuousness of abstract expression.
1860. All Year Round, No. 88. 283. He had … a broad fair face, rather vacuously good natured in its ordinary expression.
1880. Daily Tel., 14 Feb. So there he stood, with his hands in his pockets,… gazing vacuously at the fighting and rough play.
