Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. Lūca, ae, f.,
2. Lūca or Lūcas, ae, m., Lucanian; v. Lucani, D.
Lūcās, ae, m., = Λουκᾶς, St. Luke, the third evangelist, Vulg. Col. 4, 14; Prud. Apoth. 1002 et saep.