Son of a Sister
This page is the CodyCross answer for the clue below from Cruise Ship, Group 656, Puzzle 5 (Movie Night).
Question is: Son of a Sister
and the answer is: NEPHEW
Word Meaning:
NEPHEW — A son of one's sibling, brother-in-law, or sister-in-law; either a son of one's brother (fraternal nephew) or a son of one's sister (sororal nephew).
Definitions from Wiktionary.