Train System That Operates Underground
This page is the CodyCross answer for the clue below from Top Secret, Group 2081, Puzzle 5 (Spy Network).
Question is: Train System That Operates Underground
and the answer is: SUBWAY
Word Meaning:
SUBWAY — (Canada, US, Scotland, South Africa) An underground railway, especially for mass transit of people in urban areas.
Definitions from Wiktionary.