Source : Webster's Revised Unabridged Dictionary (1913)

Endorse \En*dorse"\, v. t. [imp. & p. p. {Endorsed}; p. pr. &
   vb. n. {Endorsing}.] [Formerly endosse, fr. F. endosser to
   put on the back, to endorse; pref. en- (L. in) + dos back, L.
   dorsum. See {Dorsal}, and cf. {Indorse}.]
   Same as {Indorse}.

   Note: Both endorse and indorse are used by good writers; but
         the tendency is to the more general use of indorse and
         its derivatives indorsee, indorser, and indorsement.

Endorse \En*dorse"\, n. (Her.)
   A subordinary, resembling the pale, but of one fourth its
   width (according to some writers, one eighth).

Source : WordNet®

endorse
     v 1: be behind; approve of; "He plumped for the Labor Party"; "I
          backed Kennedy in 1960" [syn: {back}, {indorse}, {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}, {indorse}]
     3: guarantee as meeting a certain standard; "certified grade
        AAA meat" [syn: {certify}, {indorse}]
     4: of documents or cheques [syn: {indorse}]