To recreate things as they were at an earlier time. For Example: If a couple is having some troubles in their relationship, one of them could say to the other, “let’s turn back the clock and just go back to when things were simpler.”

All day and all night. For Example: If someone were to say “I’ve been working round the clock,” they are saying they’ve been working non stop.

To avoid something. For Example: “I would recommend steering clear of that road, there’s a lot of construction going on right now.”

Not guilty of an offense or unobstructed by something undesirable. For Example: If someone is worried they might have their taxes audited but the date by which they expected to be audited comes and goes, they might say, “phew, I think I’m in the clear.”

Completely clean. When used in reference to a person it means they are very honest or good-hearted. For Example: “Jim would never steal from the company, he’s a squeaky clean sort of guy.”