noun

• (archaic) A living creature, especially a human being.
  "O bace gongarian wight, wilt thou the ſpicket willd?"
• (Old Norse, Germanic paganism) A supernatural being, often used in compounds such as the land-vættr which guard the land, especially the four guardians of Iceland.
• (poetic) A ghost, deity or other supernatural entity.
  "But I saw a glow-worm near, / Who replied: ‘What wailing wight / Calls the watchman of the night?"
• (fantasy) A wraith-like creature.

adj

• (archaic, except in dialects) Brave, valorous, strong.
  "I haue two sones that were but late made knyghtes / and the eldest hyghte sir Tirre /[…]/ and my yongest sone hyght Lauayne / and yf hit please yow / he shalle ryde with yow vnto that Iustes / and he is of his age x stronge and wyght"
• (UK dialectal, obsolete) Strong; stout; active.
  "Then spake Much the milner son, / Ever more well him betide! / ‘Take twelve of thy wight yeomen, / Well weapon’d by thy side. / Such one would thyselfë slon, / That twelve dare not abide.’"