Source : Webster's Revised Unabridged Dictionary (1913)

Tell \Tell\, v. i.
   1. To give an account; to make report.

            That I may publish with the voice of thankgiving,
            and tell of all thy wondrous works.   --Ps. xxvi. 7.

   2. To take effect; to produce a marked effect; as, every shot
      tells; every expression tells.

   {To tell of}.
      (a) To speak of; to mention; to narrate or describe.
      (b) To inform against; to disclose some fault of.

   {To tell on}, to inform against. [Archaic & Colloq.]

            Lest they should tell on us, saying, So did David.
                                                  --1 Sam.
                                                  xxvii. 11.