free from any dirty marks, pollution, bacteria, etc
Make sure your hands are clean before you have your dinner.
Hospitals need to be kept spotlessly (= extremely) clean.
The surgical team ensured that all instruments were sterilized to keep the operating room completely clean.
After a thorough scrub, the kitchen countertops were now clean and free from any lingering bacteria.
The laboratory technician meticulously cleaned the glassware to ensure an uncontaminated environment for experiments.
The air purification system helped keep the office clean by removing pollutants and allergens from the indoor air.
