The Collaborative International Dictionary of English v.0.48:

Hallow \Hal"low\ (h[a^]l"l[-o]), v. t. [imp. & p. p.
   Hallowed(-l[-o]d); p. pr. & vb. n. Hallowing.] [OE.
   halowen, halwien, halgien, AS. h[=a]lgian, fr. h[=a]lig holy.
   See Holy.]
   To make holy; to set apart for holy or religious use; to
   consecrate; to treat or keep as sacred; to reverence.
   "Hallowed be thy name." --Matt. vi. 9.
   [1913 Webster]

         Hallow the Sabbath day, to do no work therein. --Jer.
                                                  xvii. 24.
   [1913 Webster]

         His secret altar touched with hallowed fire. --Milton.
   [1913 Webster]

         In a larger sense . . . we can not hallow this ground
         [Gettysburg].                            --A. Lincoln.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

hallowed \hallowed\ adj.
   belonging to or derived from or associated with a divine
   power; made holy. Opposite of unholy. [Narrower terms:
   beatified, blessed ; {blessed ; {consecrated, sacred,
   sanctified ] Also See: {consecrated, consecrate, sacred.

   Syn: holy.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

hallowed
    adj 1: worthy of religious veneration; "the sacred name of
           Jesus"; "Jerusalem's hallowed soil" [syn: hallowed,
           sacred]

Moby Thesaurus II by Grady Ward, 1.0:

85 Moby Thesaurus words for "hallowed":
   acknowledged, admitted, all-knowing, all-powerful, all-seeing,
   all-wise, almighty, beatified, blessed, boundless, canonized,
   changeless, consecrated, conventional, creating, creative,
   customary, dedicated, devoted, established, eternal,
   eternally the same, everlasting, fixed, folk, glorious, good,
   handed down, heroic, highest, hoary, holy, immemorial, immortal,
   immutable, infinite, inveterate, just, legendary, limitless,
   long-established, long-standing, loving, luminous, majestic,
   making, merciful, mythological, numinous, of long standing,
   of the folk, omnipotent, omnipresent, omniscient, one, oral,
   permanent, perpetual, prescriptive, radiant, received, recognized,
   rooted, sacred, sainted, saintly, sanctified, set apart, shaping,
   sovereign, supreme, time-honored, timeless, traditional,
   tried and true, true-blue, ubiquitous, unbounded, unchanging,
   undefined, understood, unlimited, unwritten, venerable,
   worshipful