The noun is similarity.
The noun form of "similar" is "similarity."
The noun form of the verb "noun" is "noun-ness" or "nominalization."
The noun form of the word "profess" is "profession."
The noun form of the word "truthful" is "truthfulness."
The noun form for the word "proclaim" is "proclamation."
The noun form of the word "resign" is "resignation."
Similar is not a noun, it is an adjective, a word that describes a noun; for example similar outfits, similar tastes, similar backgrounds, etc.The noun form for the adjective similar is similarity.
The word debt does not have a verb form and is a noun. You can however use the word owe which is similar and is a verb.
The abstract noun form for the adjective similar is similarity.
Protein is a noun. It is any of several complex chemicals used by living things.*The similar word is the adjective protean, which has the noun form proteanism.)
The word substitute can be a verb and a noun. The verb form means to use something in place of something else. The noun form is a replacement for something which does a similar thing.
The noun form of the verb "noun" is "noun-ness" or "nominalization."
The plural form for the noun alphabet is alphabets.Example: The alphabets of both languages are very similar.
The verb form is spelled "consents" (agrees). The similar word is the noun "conscience" (moral awareness).
The noun form of the word "polite" is "politeness".
The likely word is the noun imagery (depicting a visual form).The similar word imaginary means imagined or nonexistent.
The word 'brutal' is the adjective form for the noun brute.The noun form for the adjective brutal is brutality.
The word 'daily' is a noun form as a word for a newspaper that is published every day.The word 'daily' is the adjective and adverb form of the noun day.