No, harmful is an adjective.
A verb is a word that describes an action (run, walk, etc), a state of being (exist, stand, etc) or occurrence (happen, become, etc).
An adjective is a word that describes a noun (the car is blue / it was a cold day / etc).
A noun is a word that is used to describe a person (man, lady, teacher, etc), place (home, city, beach, etc) or thing (car, banana, book, etc).
"clear-cutting" The verb is always the doing word
the crept in the house is very harmful.
The word 'pollution' is not a verb. The word pollution is a noun, a word for a substance in the environment that is harmful; a word for a thing. The verb forms are: pollute, pollutes, polluting, polluted The verb to pollute is a main verb.
"The detrimental dog kicked the harmful kitty" is a sentence - there is a subject (dog) and a verb (kicked).
The word 'harmful' is not a noun.The word 'harmful' is an adjective, a word used to describe a noun.The noun form of the adjective 'harmful' is harmfulness.The word 'harmful' is the adjective form of the noun harm.The nouns 'harmfulness' and 'harm' are both common, uncountable (mass), abstract nouns; words for concepts.The word 'harm' is also a verb: harm, harms, harming, harmed.
All Microbes are not harmful. All virus are harmful. Some bacteria are harmful
some are harmful but some are not harmful
Pollution is the abstract noun.
No they are not harmful.
The word butane is a noun. You can use a verb after it, and you can also use adjectives. For example, "Butane, a very flammable gas, if breathed in, can cause very harmful side effects".
more harmful, most harmful
lion are useful and harmful