The Collaborative International Dictionary of English v.0.48:

Issue \Is"sue\ ([i^]sh"[-u]), n. [OF. issue, eissue, F. issue,
   fr. OF. issir, eissir, to go out, L. exire; ex out of, from +
   ire to go, akin to Gr. 'ie`nai, Skr. i, Goth. iddja went,
   used as prefect of gaggan to go. Cf. Ambition, Count a
   nobleman, Commence, Errant, Exit, Eyre, Initial,
   Yede went.]
   [1913 Webster]
   1. The act of passing or flowing out; a moving out from any
      inclosed place; egress; as, the issue of water from a
      pipe, of blood from a wound, of air from a bellows, of
      people from a house.
      [1913 Webster]

   2. The act of sending out, or causing to go forth; delivery;
      issuance; as, the issue of an order from a commanding
      officer; the issue of money from a treasury.
      [1913 Webster]

   3. That which passes, flows, or is sent out; the whole
      quantity sent forth or emitted at one time; as, an issue
      of bank notes; the daily issue of a newspaper.
      [1913 Webster]

   4. Progeny; a child or children; offspring. In law,
      sometimes, in a general sense, all persons descended from
      a common ancestor; all lineal descendants.
      [1913 Webster]

            If the king
            Should without issue die.             --Shak.
      [1913 Webster]

   5. Produce of the earth, or profits of land, tenements, or
      other property; as, A conveyed to B all his right for a
      term of years, with all the issues, rents, and profits.
      [1913 Webster]

   6. A discharge of flux, as of blood. --Matt. ix. 20.
      [1913 Webster]

   7. (Med.) An artificial ulcer, usually made in the fleshy
      part of the arm or leg, to produce the secretion and
      discharge of pus for the relief of some affected part.
      [1913 Webster]

   8. The final outcome or result; upshot; conclusion; event;
      hence, contest; test; trial.
      [1913 Webster]

            Come forth to view
            The issue of the exploit.             --Shak.
      [1913 Webster]

            While it is hot, I 'll put it to the issue. --Shak.
      [1913 Webster]

   9. A point in debate or controversy on which the parties take
      affirmative and negative positions; a presentation of
      alternatives between which to choose or decide; a point of
      contention; a matter in controversy.
      [1913 Webster +PJC]

   10. (Law) In pleading, a single material point of law or fact
       depending in the suit, which, being affirmed on the one
       side and denied on the other, is presented for
       determination. See General issue, under General, and
       Feigned issue, under Feigned. --Blount. Cowell.
       [1913 Webster]

   At issue, in controversy; disputed; opposing or contesting;
      hence, at variance; disagreeing; inconsistent.
      [1913 Webster]

            As much at issue with the summer day
            As if you brought a candle out of doors. --Mrs.
                                                  Browning.


   Bank of issue, Collateral issue, etc. See under Bank,
      Collateral, etc.

   Issue pea, a pea, or a similar round body, used to maintain
      irritation in a wound, and promote the secretion and
      discharge of pus.

   To join issue, or To take issue, to take opposing sides
      in a matter in controversy.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

82 Moby Thesaurus words for "at issue":
   against the grain, against the tide, against the wind, arguable,
   at cross-purposes, at daggers, at daggers drawn, at odds,
   at variance, at war with, athwart, before the house, conditional,
   conditioned, confutable, conjectural, contestable, contingent,
   contra, contrariwise, controversial, controvertible, counter,
   cross, debatable, deniable, dependent, depending, disputable,
   doubtable, doubtful, dubious, dubitable, eyeball-to-eyeball, iffy,
   in confrontation, in debate, in dispute, in doubt, in dubio,
   in hostile array, in opposition, in question, in suspense,
   in the balance, mistakable, moot, on the agenda, on the docket,
   on the floor, on the table, open, open for discussion,
   open to doubt, open to question, pendent, pending, problematic,
   questionable, refutable, speculative, sub judice, suppositional,
   suspect, suspenseful, suspicious, uncounted, undecided,
   under active consideration, under advisement, under consideration,
   under examination, under investigation, under surveillance,
   undetermined, unestablished, unfixed, unsettled, untold,
   up for grabs, up in arms, with crossed bayonets