• (n.) A hydrocarbon radical regarded as the essential residue of naphthalene. • (n.) A hydrocarbon radical regarded as the essential residue of naphthalene. Found on http://thinkexist.com/dictionary/meaning/naphthyl/
Naph'thyl noun [ Naphth alene + -yl .] (Chemistry) A hydrocarbon radical regarded as the essential residue of naphthalene. Found on http://www.encyclo.co.uk/webster/N/3