The Collaborative International Dictionary of English v.0.48:

Anodyne \An"o*dyne\ ([a^]n"[-o]*d[imac]n), a. [L. anodynus, Gr.
   ? free from pain, stilling pain; 'an priv. + ? pain: cf. F.
   anodin.]
   Serving to assuage pain; soothing.
   [1913 Webster]

         The anodyne draught of oblivion.         --Burke.
   [1913 Webster]

   Note: "The word [in a medical sense] in chiefly applied to
         the different preparations of opium, belladonna,
         hyoscyamus, and lettuce." --Am. Cyc.
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Anodyne \An"o*dyne\, n. [L. anodynon. See Anodyne, a.]
   Any medicine which allays pain, as an opiate or narcotic;
   anything that soothes disturbed feelings.
   [1913 Webster]

WordNet (r) 3.0 (2006):

anodyne
    adj 1: capable of relieving pain; "the anodyne properties of
           certain drugs"; "an analgesic effect" [syn: analgesic,
           analgetic, anodyne]
    n 1: a medicine used to relieve pain [syn: analgesic,
         anodyne, painkiller, pain pill]

Moby Thesaurus II by Grady Ward, 1.0:

133 Moby Thesaurus words for "anodyne":
   Amytal, Amytal pill, Demerol, Dolophine, H, Luminal, Luminal pill,
   M, Mickey Finn, Nembutal, Nembutal pill, Seconal, Seconal pill,
   Tuinal, Tuinal pill, alcohol, alleviating, alleviative, alleviator,
   amobarbital sodium, analgesic, anesthetic, assuager, assuasive,
   balm, balmy, balsamic, barb, barbiturate, barbiturate pill,
   benumbing, black stuff, blue, blue angel, blue devil, blue heaven,
   blue velvet, calmant, calmative, cathartic, chloral hydrate,
   cleansing, codeine, codeine cough syrup, cushion, deadening,
   demulcent, depressant, depressor, dolly, dolorifuge, downer,
   dulling, easing, emollient, goofball, hard stuff, heroin, hop,
   horse, hypnotic, junk, knockout drops, laudanum, lenitive, liquor,
   lotus, meperidine, methadone, mitigating, mitigative, mitigator,
   moderator, modulator, mollifier, morphia, morphine, narcotic,
   nepenthe, numbing, opiate, opium, pacificator, pacifier,
   pain killer, pain-killer, pain-killing, palliative, paregoric,
   peacemaker, pen yan, phenobarbital, phenobarbital sodium,
   purgative, purple heart, quietener, quietening, rainbow, red,
   relieving, remedial, restraining hand, salve, scag,
   secobarbital sodium, sedative, shit, shock absorber, sleep-inducer,
   sleep-inducing, sleeper, sleeping draught, sleeping pill, smack,
   sodium thiopental, softening, somnifacient, somniferous, soother,
   soothing, soothing syrup, soporific, stabilizer, subduing, tar,
   temperer, tranquilizer, tranquilizing, turps, white stuff,
   wiser head, yellow, yellow jacket