to indorse in blank

Indorse \In*dorse"\, v. t. [imp. & p. p. {Indorsed}; p. pr. &
   vb. n. {Indorsing}.] [LL. indorsare. See {Endorse}.] [Written
   also {endorse}.]
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   1. To cover the back of; to load or burden. [Obs.]
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            Elephants indorsed with towers.       --Milton.
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   2. To write upon the back or outside of a paper or letter, as
      a direction, heading, memorandum, or address.
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   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 note,
      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.).
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   4. To give one's name or support to; to sanction; to aid by
      approval; to approve; as, to indorse an opinion.
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   {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.
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