tunnel
noun
an underground passage.
had been tunneling
-
past perfect progressiveof tunnel.past perfect progressive
Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The seismic shaking could mean that magma had been tunneling underground for up to a decade before the volcanic islands appeared, the researchers said.
From Scientific American ● May 30, 2015
As early as Day One of the hostage standoff, diggers had been tunneling underneath the theater in preparation for an assault.
From Time Magazine Archive
