The Collaborative International Dictionary of English v.0.48:

Alternate \Al*ter"nate\ (?; 277), a. [L. alternatus, p. p. of
   alternate, fr. alternus. See Altern, Alter.]
   1. Being or succeeding by turns; one following the other in
      succession of time or place; by turns first one and then
      the other; hence, reciprocal.
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            And bid alternate passions fall and rise. --Pope.
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   2. Designating the members in a series, which regularly
      intervene between the members of another series, as the
      odd or even numbers of the numerals; every other; every
      second; as, the alternate members 1, 3, 5, 7, etc.; read
      every alternate line.
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   3. (Bot.) Distributed, as leaves, singly at different heights
      of the stem, and at equal intervals as respects angular
      divergence. --Gray.
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   Alternate alligation. See Alligation.

   Alternate angles (Geom.), the internal and angles made by
      two lines with a third, on opposite sides of it. It the
      parallels AB, CD, are cut by the line EF, the angles AGH,
      GHD, as also the angles BGH and GHC, are called alternate
      angles.

   Alternate generation. (Biol.) See under Generation.
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