Source : Webster's Revised Unabridged Dictionary (1913)

Indorse \In*dorse"\, v. t. [imp. & p. p. {Indorsed}; p. pr. &
   vb. n. {Indorsing}.] [LL. indorsare. See {Endorse}.] [Written
   also {endorse}.]
   1. To cover the back of; to load or burden. [Obs.]

            Elephants indorsed with towers.       --Milton.

   2. To write upon the back or outside of a paper or letter, as
      a direction, heading, memorandum, or address.

   3. (Law & Com.) To write one's name, alone or with other
      words, upon the back of (a paper), for the purpose of
      transferring it, or to secure the payment of a ?ote,
      draft, or the like; to guarantee the payment, fulfillment,
      performance, or validity of, or to certify something upon
      the back of (a check, draft, writ, warrant of arrest,
      etc.).

   4. To give one's name or support to; to sanction; to aid by
      approval; to approve; as, to indorse an opinion.

   {To indorse in blank}, to write one's name on the back of a
      note or bill, leaving a blank to be filled by the holder.

Source : WordNet®

indorse
     v 1: be behind; approve of; "He plumped for the Labor Party"; "I
          backed Kennedy in 1960" [syn: {back}, {endorse}, {plump
          for}, {plunk for}, {support}]
     2: give support or one's approval to; "I'll second that
        motion"; "I can't back this plan"; "endorse a new project"
        [syn: {second}, {back}, {endorse}]
     3: guarantee as meeting a certain standard; "certified grade
        AAA meat" [syn: {certify}, {endorse}]
     4: of documents or cheques [syn: {endorse}]