Crossword clue: a passageway through or under something, usually underground (especially one for trains or cars)

The most common answer is tunnel (6 letters).

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

tunnel 6 letters wn-def

a passageway through or under something, usually underground (especially one for trains or cars)