The Collaborative International Dictionary of English v.0.48:

Godliness \God"li*ness\, n. [From Godly.]
   Careful observance of, or conformity to, the laws of God; the
   state or quality of being godly; piety.
   [1913 Webster]

         Godliness is profitable unto all things. --1 Tim. iv.
                                                  8.
   [1913 Webster]

WordNet (r) 3.0 (2006):

godliness
    n 1: piety by virtue of being a godly person [ant:
         godlessness, ungodliness]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "godliness":
   Christianity, Christlikeness, Christliness, Fatherhood,
   angelicalness, awesomeness, awfulness, beauty of holiness,
   blessedness, deity, divineness, divinity, fear of God, godhead,
   godhood, godlikeness, godly-mindedness, godship, goodness,
   hallowedness, heavenliness, heavenly-mindedness, holiness,
   holy-mindedness, ineffability, inenarrability, inexpressibility,
   inviolability, inviolableness, moral rectitude, morale, morality,
   numinousness, odor of sanctity, otherworldliness, probity,
   pureness, pureness of heart, purity, rectitude, right conduct,
   righteousness, sacredness, sacrosanctity, sacrosanctness,
   sainthood, saintlikeness, saintliness, saintship, sanctitude,
   sanctity, seraphicalness, spiritual-mindedness, spirituality,
   unearthliness, unspeakability, unutterability, unworldliness,
   venerability, venerableness, virtue, virtuousness



Easton's 1897 Bible Dictionary:

Godliness
   the whole of practical piety (1 Tim. 4:8; 2 Pet. 1:6). "It
   supposes knowledge, veneration, affection, dependence,
   submission, gratitude, and obedience." In 1 Tim. 3:16 it denotes
   the substance of revealed religion.