The Collaborative International Dictionary of English v.0.48:

Hag \Hag\, v. t. [imp. & p. p. Hagged (h[a^]gd); p. pr. & vb.
   n. Hagging.]
   To harass; to weary with vexation.
   [1913 Webster]

         How are superstitious men hagged out of their wits with
         the fancy of omens.                      --L'Estrange.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hag \Hag\, n. [Scot. hag to cut; cf. E. hack.]
   1. A small wood, or part of a wood or copse, which is marked
      off or inclosed for felling, or which has been felled.
      [1913 Webster]

            This said, he led me over hoults and hags;
            Through thorns and bushes scant my legs I drew.
                                                  --Fairfax.
      [1913 Webster]

   2. A quagmire; mossy ground where peat or turf has been cut.
      --Dugdale.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hag \Hag\ (h[a^]g), n. [OE. hagge, hegge, witch, hag, AS.
   h[ae]gtesse; akin to OHG. hagazussa, G. hexe, D. heks, Dan.
   hex, Sw. h[aum]xa. The first part of the word is prob. the
   same as E. haw, hedge, and the orig. meaning was perh., wood
   woman, wild woman. [root]12.]
   1. A witch, sorceress, or enchantress; also, a wizard. [Obs.]
      "[Silenus] that old hag." --Golding.
      [1913 Webster]

   2. An ugly old woman. --Dryden.
      [1913 Webster]

   3. A fury; a she-monster. --Crashaw.
      [1913 Webster]

   4. (Zool.) An eel-like marine marsipobranch (Myxine
      glutinosa), allied to the lamprey. It has a suctorial
      mouth, with labial appendages, and a single pair of gill
      openings. It is the type of the order Hyperotreta.
      Called also hagfish, borer, slime eel, sucker, and
      sleepmarken.
      [1913 Webster]

   5. (Zool.) The hagdon or shearwater.
      [1913 Webster]

   6. An appearance of light and fire on a horse's mane or a
      man's hair. --Blount.
      [1913 Webster]

   Hag moth (Zool.), a moth (Phobetron pithecium), the larva
      of which has curious side appendages, and feeds on fruit
      trees.

   Hag's tooth (Naut.), an ugly irregularity in the pattern of
      matting or pointing.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hagdon \Hag"don\ (h[a^]g"d[o^]n), n. (Zool.)
   One of several species of sea birds of the genus Puffinus;
   esp., Puffinus major, the greater shearwarter, and
   Puffinus Stricklandi, the black hagdon or sooty shearwater;
   -- called also hagdown, haglin, and hag. See
   Shearwater.
   [1913 Webster]

WordNet (r) 3.0 (2006):

hag
    n 1: an ugly evil-looking old woman [syn: hag, beldam,
         beldame, witch, crone]
    2: eellike cyclostome having a tongue with horny teeth in a
       round mouth surrounded by eight tentacles; feeds on dead or
       trapped fishes by boring into their bodies [syn: hagfish,
       hag, slime eels]

Moby Thesaurus II by Grady Ward, 1.0:

69 Moby Thesaurus words for "hag":
   Jezebel, Weird Sisters, baboon, bag, bat, battle-ax, beldam, biddy,
   bitch-kitty, blemish, blot, coven, crone, dame, dog, dowager, drab,
   enchantress, eyesore, fishwife, fright, frump, fury, gammer,
   gargoyle, gorgon, grandam, grandmother, granny, grimalkin, harpy,
   harridan, hellcat, hellhag, hex, lamia, mess, monster, monstrosity,
   no beauty, old battle-ax, old dame, old girl, old granny, old lady,
   old trot, old wife, old woman, scarecrow, shamaness, she-devil,
   she-wolf, shrew, sight, siren, slattern, sorceress, teratism,
   termagant, tigress, trot, ugly duckling, virago, vixen, war-horse,
   wildcat, witch, witchwife, witchwoman



The Devil's Dictionary (1881-1906):

HAG, n.  An elderly lady whom you do not happen to like; sometimes
called, also, a hen, or cat.  Old witches, sorceresses, etc., were
called hags from the belief that their heads were surrounded by a kind
of baleful lumination or nimbus -- hag being the popular name of that
peculiar electrical light sometimes observed in the hair.  At one time
hag was not a word of reproach:  Drayton speaks of a "beautiful hag,
all smiles," much as Shakespeare said, "sweet wench."  It would not
now be proper to call your sweetheart a hag -- that compliment is
reserved for the use of her grandchildren.