Wordnet 3.0
ADJECTIVE (1)
1. 
 stuck in a place where a ship can no longer float; 
- Example: "a ship aground offshore"- Example: "a boat aground on the beach waiting for the tide to lift it"ADVERB (1)
1. 
 with the bottom lodged on the ground; 
- Example: "he ran the ship aground"
The Collaborative International Dictionary of English v.0.48:
Aground \A*ground"\, adv. & a. [Pref. a- + ground.]
   On the ground; stranded; -- a nautical term applied to a ship
   when its bottom lodges on the ground. --Totten.
   [1913 Webster]
WordNet (r) 3.0 (2006):
aground
    adv 1: with the bottom lodged on the ground; "he ran the ship
           aground"
    adj 1: stuck in a place where a ship can no longer float; "a
           ship aground offshore"; "a boat aground on the beach
           waiting for the tide to lift it" [ant: afloat(p)]
Moby Thesaurus II by Grady Ward, 1.0:
31 Moby Thesaurus words for "aground":
   anchored, beached, castaway, caught, chained, fast, fastened,
   fixed, foundered, grounded, hard and fast, held, high and dry,
   impacted, inextricable, jammed, marooned, moored, on the rocks,
   packed, set fast, shipwrecked, stranded, stuck, stuck fast,
   swamped, tethered, tied, transfixed, wedged, wrecked