The Collaborative International Dictionary of English v.0.48:

Yearn \Yearn\ (y[~e]rn), v. t. [imp. & p. p. Yearned; p. pr. &
   vb. n. Yearning.] [Also earn, ern; probably a corruption of
   OE. ermen to grieve, AS. ierman, yrman, or geierman, geyrman,
   fr. earm wretched, poor; akin to D. & G. arm, Icel. armr,
   Goth. arms. The y- in English is perhaps due to the AS. ge
   (see Y-).]
   To pain; to grieve; to vex. [Obs.] "She laments, sir, for it,
   that it would yearn your heart to see it." --Shak.
   [1913 Webster]

         It yearns me not if men my garments wear. --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

yearning \yearn"ing\, n.
   1. prolonged unfulfilled desire or need.

   Syn: longing.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

yearning \yearn"ing\, adj.
   1. full of longing or unfulfilled desire.

   Syn: wistful.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

yearning
    n 1: prolonged unfulfilled desire or need [syn: longing,
         yearning, hungriness]

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "yearning":
   Amor, Christian love, Eros, Heimweh, Platonic love, aching,
   admiration, adoration, affection, agape, ardency, ardor,
   attachment, bodily love, brotherly love, caritas, charity,
   conjugal love, desiderium, desire, devotion, faithful love, fancy,
   fervor, flame, fondness, free love, free-lovism, hankering, heart,
   hero worship, homesick, homesickness, honing, idolatry, idolism,
   idolization, languishing, languishment, lasciviousness, libido,
   like, liking, longing, love, lovemaking, mal du pays,
   maladie du pays, married love, nostalgia, nostalgic, nostomania,
   passion, physical love, pining, popular regard, popularity, regard,
   sentiment, sex, sexual love, shine, spiritual love, tender feeling,
   tender passion, truelove, uxoriousness, weakness, wishful, wistful,
   worship, yearnful, yen