[1] : The Collaborative International Dictionary of English v.0.48

sooth \sooth\ s=ooth, a.; also adv. compar. soother
   s=ooth"~er; superl. soothest. oe. soth, as.
   s=oeth, for saneth; akin to os. s=oeth, ohg. sand,
   icel. sannr, sw. sann, dan. sand, skr. sat, sant, real,
   genuine, present, being; properly p. pr. from a root meaning,
   to be, skr. as, l. esse; also akin to goth. sunjis true, gr.
   'eteo`s, skr. satya. root9. cf. absent, am, essence,
   is, soothe, sutee.
   1. true; faithful; trustworthy. obs. or scot.
      1913 webster

            the sentence meaning of it sooth is, out of doubt.
                                                  --chaucer.
      1913 webster

            that shall i sooth said he to you declare.
                                                  --spensser.
      1913 webster

   2. pleasing; delightful; sweet. r.
      1913 webster

            the soothest shepherd that ever piped on plains.
                                                  --milton.
      1913 webster

            with jellies soother than the creamy curd. --keats.
      1913 webster
see also:
soother soothest absent am essence is 
soothe sutee 

[2] : The Collaborative International Dictionary of English v.0.48

sooth \sooth\, n. as. s=oeth. see sooth, a.
   1. truth; reality. archaic
      1913 webster

            the sooth it this, the cut fell to the knight.
                                                  --chaucer.
      1913 webster

            in sooth, i know not why i am so sad. --shak.
      1913 webster

            in good sooth,
            its mystery is love, its meaninng youth.
                                                  --longfellow.
      1913 webster

   2. augury; prognostication. obs.
      1913 webster

            the soothe of birds by beating of their wings.
                                                  --spenser.
      1913 webster

   3. blandishment; cajolery. obs. --shak.
      1913 webster
see also:
sooth 

[3] : WordNet (r) 2.0

sooth
     n : truth or reality; "in sooth"

Sooth >> S Words
Sooth, definition of term: Sooth
sooth_pag1.html