a. and sb. Also 6 Stygion, 67 stigian, 7 stigean, (stageoun). [f. L. Stygi-us (a. Gr. Στύγιος, f. Στυγ-: see STYX) + -AN. Cf. F. Stygien.] A. adj.
1. Pertaining to the river Styx, or, in wider sense, to the infernal regions of classical mythology.
Stygian Jove, Jupiter (= L. Juppiter Stygius): Pluto, the god of the lower world.
1566. Studley, Agam., 545. Wher as the stygion porter doth aduaunce with lustye crakes.
1590. Spenser, F. Q., II. vii. 27. If euer he transgrest the fatall Stygian lawes.
1594. Kyd, Cornelia, III. i. 138. It eyther turneth to the Stygian Lake, Or staies for euer in th Elisian fields.
1602. Narcissus (1893), 658. Stray, soule vnto the Stingian [sic] strand.
1606. Shaks., Tr. & Cr., III. ii. 10. Like a strange soule upon the Stygian bankes Staying for waftage.
c. 1610. Sir J. Semple, in Sempill Ballatis (1872), 242. I sweere by the stageoun stankes of hell, by which the gods do sweir.
1631. Knevet, Rhodon & Iris, V. iii. H 3.
| Where by thy ignorant conduct and base carriage, | |
| Thou maist a thousand heroicke soules send packing | |
| Vnto the Stygian shore. | 
1667. Milton, P. L., III. 14. Thee [holy light] I re-visit now with bolder wing, Escapt the Stygian Pool, though long detaind In that obscure sojourn.
1697. Dryden, Æneis, IV. 916. Thus will I pay, my Vows, to Stygian Jove.
1827. Hood, Ode to Melancholy, 49. Ay, let us think of Him a while, That, with a coffin for a boat, Rows daily oer the Stygian moat.
1860. Thackeray, Lovel, vi. (1861), 225. In that omnibus I had been carried over to tother side of the Stygian Shore. I returned but as a passionless ghost.
1900. Bridges, Recoll. Solit., 49. Ere ye the mournful Stygian river crost.
transf. and fig. 1600. W. Watson, Decacordon (1602), 46. As men inuolued in laberinths of errours, drowne themselues in the Stigean lake of their owne folly.
1802. Britton & Brayley, Beauties Eng., III. 111. The plain [near Solway Moss] that was covered by this stygian torrent, has since been reclaimed.
1879. Farrar, St. Paul, I. II. vii. 119. Content to wallow, like natural brute beasts, in the Stygian pool of a hideous immorality.
b. Of an oath: Supremely binding, inviolable like the oath by the Styx, which the gods themselves feared to break.
1608. Chapman, Byrons Trag., V. ii. P 3. His vowes And othes so Stygian.
1647. H. More, Philos. Poems, 301. But O that envious Destinie, Or Stygian vow, or thrice accursed charm Should [etc.].
1682. Sir T. Browne, Chr. Mor., III. xvi. (1716), 104. They [astrologers] Kill us not with Stygian Oaths and merciless necessity, but leave us hopes of evasion. Ibid., xix. 107. But Honest Mens Words are Stygian Oaths, and Promises inviolable.
2. Infernal, hellish.
1601. Yarington, Two Lament. Trag., IV. viii. in Bullen, O. Pl. IV. We have such evidence, To ratifie your Stigian cruelty, That cannot be deluded any way.
a. 1627. Middleton, Mayor Queenb., V. ii. If this be not the man, whose Stygian Soul Breathd forth that counsel to me.
1635. Quarles, Emblems, I. x. Sometime they whoop, sometimes their Stygian cries Send their black-Santos to the blushing skies.
1648. Jenkyn, Blind Guide, i. 3. I know not one left him to contend with for mastery in the art of lying , unlesse it be his stygian teacher.
a. 1652. J. Smith, Sel. Disc., ii. 32. The broad gates of hell are opened, the rivers of fire and Stygian inundations run down as a swelling flood.
1663. Dryden, Wild Gallant, I. ii. What a Stygian womans this, to talk thus?
1667. Milton, P. L., X. 453. Amazd At that so sudden blaze the Stygian throng Bent thir aspect.
1784. Cowper, Task, III. 738. To be preferred to smoke, to the eclipse That Metropolitan volcanoes make, Whose Stygian throats breathe darkness all day long.
1876. T. Hardy, Hand Ethelberta, xxvii. But what Stygian sound was this? We are close to a kennel of hounds, said Ethelberta.
3. Black as the river Styx; dark or gloomy as the region of the Styx.
1599. Marston, Antonios Rev., I. i. Will I not turne a glorious bridall morne Unto a Stygian night?
1634. Milton, Comus, 134. Mysterious Dame, That nere art calld, but when the Dragon woom Of Stygian darknes spets her thickest gloom.
1742. Young, Nt. Th., VI. 80. Life In stronger thread of brighter colour spun ; dipt by cruel fate In Stygian dye, how black, how brittle here!
1814. Wordsw., Laodamia, 66. The conscious Parcæ threw Upon those roseate lips a Stygian hue.
1876. Emerson, Lett. & Soc. Aims, Immortality, Wks. (Bohn), III. 277. Swedenborg announced many things true and admirable, though always clothed in somewhat sad and Stygian colours.
1910. Bible in World, Jan., 28/1. Old prints show us the Irwell, whose stygian waters are now walled in , flowing through green fields and wooded banks.
† 4. Stygian water, liquor [trans. mod.L. aqua Stygia]: in Old Chemistry, a name for nitrohydrochloric acid and other strong mineral acids. Also applied to virulent poisons. Stygian liquor (jocularly): a black nauseous drink. Obs.
1638. Sir T. Herbert, Trav. (ed. 2), 220. In the evening many Mussulmen assemble to sip a sort of Stigian liquour; a black, thick, bitter potion, brewed out of Bunchie or Bunnu berries.
a. 1661. Boyle, Cert. Physiol. Ess., iv. (1669), 140. Upon the mixture of these two Liquors there also obtrudes it self upon the Sense a very strong and offensive smell which perhaps occasiond some Chymists to call a Menstruum (wherein that nitrous spirit and smell is predominant) the Stygian water.
1706. Phillips (ed. Kersey), Stygian Liquors, are Acid Spirits, so calld by Chymists, from their Power to destroy or dissolve Mixt Bodies.
1797. W. Johnston, trans. Beckmanns Invent., I. 100. The means Mr. Bell employed to analyse these stygian drops. Ibid., 101. That there are more kinds than one of this stygian water. Ibid., II. 44. The horns of a Scythian animal, in which the Stygian water that destroyed every other vessel could be contained.
B. sb. A dweller by the Styx. nonce-use.
1860. Thackeray, Roundabout P., Desseins. And so even among these Stygians this envy and quarrelsomeness survive?