Filius

Latin term for "son." The term may appear spelled several different ways in historical documents according to its grammatical usage in the sentence, as shown in the following table:

 Case  Singular  Plural
 Nominative  filius  filii
 Vocative  filie  filii
 Accusative  filium  filios
 Genitive  filii  filiorum
 Dative  filio  filiis
 Ablative  filio  filiis