underground

"My brother uses the underground to get to work every day. "

"My brother took the underground to work this morning. "

"The new underground connects the city center to the university campus. "

"To get to school quickly, the students used the underground walkway. "

"The construction crew worked on the underground, laying new sewer pipes. "

"The spelunkers explored the fascinating underground caves. "

"the French underground during World War II"

"The underground was active in promoting alternative music at the school. "

"The city is undergrounding the power cables to reduce the risk of outages. "

"There is an underground tunnel that takes you across the river."

"These criminals operate through an underground network."

"underground music"

"The tunnel goes underground at this point."

"The student planned the surprise party underground, keeping it a secret from everyone. "