Source : Webster's Revised Unabridged Dictionary (1913)

Sooth \Sooth\ (s[=oo]th), a.; also adv. [Compar. {Soother}
   (s[=oo]th"[~e]r); superl. {Soothest}.] [OE. soth, AS.
   s[=o][eth], for san[eth]; akin to OS. s[=o][eth], 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. [root]9. Cf. {Absent}, {Am}, {Essence},
   {Is}, {Soothe}, {Sutee}.]
   1. True; faithful; trustworthy. [Obs. or Scot.]

            The sentence [meaning] of it sooth is, out of doubt.
                                                  --Chaucer.

            That shall I sooth (said he) to you declare.
                                                  --Spensser.

   2. Pleasing; delightful; sweet. [R.]

            The soothest shepherd that ever piped on plains.
                                                  --Milton.

            With jellies soother than the creamy curd. --Keats.