The phrase "ticking clock" refers to a situation where time is running out and there is a deadline approaching. It symbolizes the pressure and urgency to complete a task before it's too late.
Sentences with «ticking clock»
They, at least, can tell time as the minutes tick by in this clock - stopping ticking clock thriller. (rogersmovienation.com)
Oh well, at least this reboot has the same ticking clock efficiency as the original show. (detroitnews.com)
A silence made itself felt, the kind that, because it should have been marked by a slowly ticking clock, almost was. (slaw.ca)