The Collaborative International Dictionary of English v.0.48:

Lull \Lull\ (l[u^]l), v. t. [imp. & p. p. Lulled (l[u^]ld); p.
   pr. & vb. n. Lulling.] [Akin to OD. lullen to sing to
   sleep, G. lullen, Dan. lulle, Sw. lulla; all of imitative
   origin. Cf. Loll, Lollard.]
   To cause to rest by soothing influences; to compose; to calm;
   to soothe; to quiet. " To lull him soft asleep." --Spenser.
   [1913 Webster]

         Such sweet compulsion doth in music lie,
         To lull the daughters of necessity.      --Milton.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

60 Moby Thesaurus words for "lulling":
   abatement, allayment, alleviation, analgesia, anesthesia,
   anesthetizing, appeasement, appeasing, assuagement, blunting,
   calming, cradling, damping, deadening, demulsion, diminishment,
   diminution, dreamy, drowsy, dulcification, dulling, ease, easement,
   easing, falling-off, gentling, hushing, leniency, lessening,
   letdown, letup, lightening, loosening, mitigation, modulation,
   mollification, mollifying, numbing, pacification, pacifying,
   palliation, quietening, quieting, reduction, relaxation, relief,
   remedy, remission, restful, rocking, salving, slackening,
   softening, soothful, soothing, stilling, subduement, tempering,
   tranquilization, tranquilizing