هذا التحديد واضح.

هذا means this and is the masculine singular demonstrative in Arabic.

It is used here because التحديد is:

• singular
• masculine
• a non-human noun

So هذا التحديد means this specification / this definition / this determination, depending on context.

التحديد is a noun. It comes from the root ح د د, which often has meanings related to defining, specifying, determining, limiting.

The pattern here forms a verbal noun (also called a maṣdar), so التحديد can mean things like:

• the specification
• the definition
• the determination
• the delimitation

The exact English translation depends on context.

The prefix الـ is the definite article, equivalent to the in English.

So:

• تحديد = a specification / specification
• التحديد = the specification

In this sentence, the noun is definite because it has الـ, and that fits naturally with هذا, since demonstrative phrases like this X are definite.

Because واضح is the predicate of the sentence, not part of a noun phrase like the clear specification.

This sentence is a nominal sentence:

• هذا التحديد = the topic / subject
• واضح = the predicate (clear)

So it means:

• This specification is clear

If you said هذا التحديد الواضح, that would usually mean:

• this clear specification

That is a different structure.

Because it agrees with التحديد, which is masculine singular.

In Arabic, adjectives and predicate adjectives usually agree with the noun in:

• gender
• number
• definiteness (when used attributively)

Here واضح is masculine singular because التحديد is masculine singular.

For comparison:

• هذه الفكرة واضحة = This idea is clear
  • واضحة is feminine singular because الفكرة is feminine

Yes. In the present tense, Arabic often uses nominal sentences with no written word for is.

So:

• هذا التحديد واضح literally looks like:
• this specification clear

But it means:

• This specification is clear

Arabic usually leaves out the present-tense is/are in sentences like this.

In standard Arabic, هذا التحديد واضح is the normal and natural order for this specification is clear.

Putting the demonstrative after the noun, as in التحديد هذا, is not the standard MSA way for this meaning. Post-nominal demonstratives are much more common in spoken dialects than in formal Modern Standard Arabic.

So for MSA, stick with:

• هذا التحديد واضح

In full case-marked MSA, it would normally be:

هٰذَا التَّحْدِيدُ وَاضِحٌ

The endings are:

• هذا — fixed form here
• التحديدُ — nominative, because it is the subject/topic of the nominal sentence
• واضحٌ — nominative, because it is the predicate

In everyday writing, these final short vowels are usually omitted.

It is pronounced at-taḥdīd, not al-taḥdīd.

That is because ت is a sun letter. With sun letters, the l of الـ is not pronounced, and the following consonant is doubled.

So:

• written: التحديد
• pronounced: at-taḥdīd

This is an important pronunciation rule in Arabic.

They are the same adjective in different gender forms:

• واضح = masculine singular
• واضحة = feminine singular

Since التحديد is masculine, the sentence uses واضح.

Compare:

• هذا التحديد واضح = masculine noun
• هذه النتيجة واضحة = feminine noun

In learning materials, it is often easiest to treat هذا التحديد as one noun phrase meaning this specification.

More traditional grammar can analyze the structure more finely, but for most learners the useful takeaway is:

• هذا + definite noun = this + noun
• together they function as the subject/topic here

So in practice:

• هذا التحديد = this specification
• واضح = is clear

Yes. Depending on context, واضح can also mean:

• obvious
• evident
• plain
• explicit

So the sentence could sometimes be understood as:

• This specification is obvious
• This definition is clear
• This determination is evident

The best choice depends on how التحديد is being used in context.