"Either" is a conjunction. More specifically, it is a correlative conjunction.
It is a pronoun -- either interrogative or relative.
The word "brief", depending on context, can be either a verb, a noun, or an adjective.
The part of speech that the word my is used as is an adjective.
It can be either a noun or an adjective, depending upon its use in a sentence.
A suffix changes a word's part of speech. For example, the word 'happy' is an adjective. But when you add a suffix, which is an ending, it can change the part of speech. Happily is an adverb. Happiness is a noun.
It is a pronoun -- either interrogative or relative.
"Fear" can be either a noun or a verb.
The word "brief", depending on context, can be either a verb, a noun, or an adjective.
Caption can be either a noun (object) or a verb (action).
Noun
The word "allocated" is a verb, specifically the past tense form of the verb "allocate." It is used to describe the action of assigning or distributing something for a specific purpose.
The word "constraint" is a noun. The word "design" can be either a noun or a verb but in this context it is a noun.
The word "constraint" is a noun. The word "design" can be either a noun or a verb but in this context it is a noun.
The part of speech for this particular word is a noun.
The part of speech that the word my is used as is an adjective.
"Design constraint" is a noun phrase. It refers to limitations or requirements that influence the design process.
H is a letter, not a word. To be a part of speech, it needs to be a word.