a preparation used in cleaning something
"After scrubbing the kitchen floor, I noticed that the old oil stain remained until she applied her favorite citrus-based cleaner."
the operator of dry-cleaning establishment
"The cleaner at the shop forgot to check my suit for stains before folding it."
someone whose occupation is cleaning
"The hotel cleaner apologized for missing a spot on the bathroom mirror during her morning rounds."
A person whose occupation is to clean floors, windows and other things.
"The building manager hired a cleaner to scrub the lobby windows before the holiday opening."
In plain English: A cleaner is someone whose job is to make places tidy and remove dirt.
"We hired a cleaner to tidy up the kitchen before we moved in."
Usage: Use cleaner as a noun to refer to a person employed to maintain cleanliness in buildings or homes. It is distinct from the adjective form, which describes something free from dirt or impurities.
comparative form of clean: more clean
"The new mop left a much cleaner floor than the old raggy one I used yesterday."
In plain English: Something that is cleaner has been washed or cleaned so it looks fresh and free of dirt.
"The cleaner the streets, the better for everyone walking there."
Usage: Do not use "cleaner" as a comparative adjective before a noun (e.g., "a cleaner car") because English requires "cleaner" to be placed after the noun or with "than." Instead, say "a more clean car," though this phrasing is awkward; it is often better to rephrase the sentence entirely using "cleaner" as a noun or simply repeat the adjective if comparison is necessary.
The word cleaner comes from the Old English root clæn, meaning pure or unstained. It entered modern usage by adding the agent suffix -er to the base word "clean" to describe someone who performs that action.