Interest coverage tells you how easily a business pays the interest on its debt. It divides yearly operating profit by the yearly interest bill, so a value of 10 times means the company earns ten times what it owes in interest each year, plenty of cushion. Read it like a household: if your salary is ten times your loan payments, you are comfortable; if it barely equals them, one bad month breaks you.
As a guide: above 6 times is comfortable, 3 to 6 times is adequate, and below 1.5 times is a danger zone. Below 1 times means current profits cannot even cover the interest, so the business is falling behind just standing still. The best businesses often sit at 20 times or more, or have no interest bill at all because they carry no debt.
One subtlety for companies in a heavy build-out phase (utilities, telecoms, real estate): accounting rules let some interest be counted as part of the cost of what is being built rather than as an expense, which makes this ratio look better than the real interest burden. Credit analysts add that hidden interest back.