Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† pissĭnus, a, um, adj., = πισσινος, of pitch, pitch-: e pice fit (oleum) quod pissinum appellant, Plin. 15, 7, 7, § 31; 23, 4, 50, § 96; 25, 5, 22, § 55.