The Collaborative International Dictionary of English v.0.48:

Squinance \Squin"ance\ (skw[i^]n"ans), Squinancy \Squin"an*cy\
   (-an*s[y^]), n. [F. esquinancie, OF. squinance, esquinance.
   See Quinsy.]
   1. (Med.) The quinsy. See Quinsy. [Obs.]
      [1913 Webster]

   2. (Bot.) A European perennial herb (Asperula cynanchica)
      with narrowly linear whorled leaves; -- formerly thought
      to cure the quinsy. Also called quincewort.
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   Squinancy berries, black currants; -- so called because
      used to cure the quinsy. --Dr. Prior.
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The Collaborative International Dictionary of English v.0.48:

Quinsy \Quin"sy\, n. [Contr. fr. squinancy, F. esquinancie, L.
   cynanche a sort of sore throat, Gr. ? sore throat, dog
   quinsy, fr. ? dog + ? to choke; cf. also L. synanche sore
   throat, Gr. ?. Cf. Hound, Anger, and Cynanche.] (Med.)
   An inflammation of the throat, or parts adjacent, especially
   of the fauces or tonsils, attended by considerable swelling,
   painful and impeded deglutition, and accompanied by
   inflammatory fever. It sometimes creates danger of
   suffocation; -- called also squinancy, and squinzey.
   [1913 Webster]