Is Child hood a noun

Yes, the Word 'childhood' is a noun, a Word for a period in a person's life; a Word for a thing.
The noun 'childhood' is a closed compound noun (no space); a noun made up of two or more Words that form a noun with a meaning of its own.
The noun 'childhood' is a common noun, a general Word for the childhood of anyone, anywhere. A common noun is capitalized only when it is the first Word in a sentence.