Þetta orð er nafnorð.

Here þetta means this.

In Þetta orð, it is a demonstrative modifying orð, so the whole phrase means this word.

Because orð is a neuter singular noun, and þetta is the neuter singular nominative/accusative form of this.

Icelandic demonstratives must agree with the noun in:

• gender
• number
• case

So:

• masculine singular: þessi
• feminine singular: þessi
• neuter singular: þetta

Since orð is neuter singular, þetta orð is the correct form.

Orð is neuter.

That matters because it affects the form of words around it, such as þetta. Icelandic nouns belong to grammatical genders:

• masculine
• feminine
• neuter

Here, the neuter gender is the reason you get þetta orð.

It is singular nominative.

In this sentence, Þetta orð is the subject, so orð appears in the nominative case.

A useful thing to know is that many Icelandic neuter nouns often have the same form in the singular nominative and accusative, so orð does not visibly change here.

Because Icelandic does not have a separate indefinite article like English a/an.

So nafnorð can mean:

• a noun
• sometimes just noun, depending on context

That is completely normal in Icelandic.

Because after the verb vera (to be), Icelandic often uses a predicate noun in the nominative.

So in:

• Þetta orð = subject
• er = is
• nafnorð = predicate noun

Both the subject and the predicate noun are nominative here.

Er is the present tense, 3rd person singular form of vera (to be).

So it corresponds to English is.

Examples:

• Hann er kennari. — He is a teacher.
• Hún er hér. — She is here.
• Þetta orð er nafnorð. — This word is a noun.

This is the normal basic Icelandic word order for a simple statement:

• subject: Þetta orð
• verb: er
• complement: nafnorð

So it follows a straightforward Subject–Verb–Complement pattern, very similar to English.

Yes, but it means something slightly different.

• Þetta orð er nafnorð. = This word is a noun.
• Þetta er nafnorð. = This is a noun.

The second sentence does not explicitly say word. It could still refer to a word, but the original sentence is more specific.

Yes. Nafnorð is historically made from:

• nafn = name
• orð = word

So it is literally something like name-word, which is the Icelandic grammatical term for noun.

Icelandic uses many transparent compound words like this.

A rough guide:

• þ is like th in thin
• ð is like th in this (though in Icelandic it can be softer or less fully pronounced depending on position)

So roughly:

• Þetta ≈ THET-ta
• orð ≈ orth / orð
• nafnorð ≈ NAPN-orth

This is only an approximation, but it is a good starting point for English speakers.

In a normal noun phrase, the demonstrative usually comes before the noun:

• þetta orð = this word

That is the standard order. Putting it after the noun would not be the normal basic pattern here.

No, not in gender.

Nafnorð is not an adjective describing orð. It is a predicate noun telling you what orð is.

So the important thing here is not gender agreement, but the fact that nafnorð is in the correct case for this construction, namely the nominative.

Because þetta orð already means this word, and Icelandic normally does not add the suffixed definite article to a noun when a demonstrative like þetta is used.

So:

• orð = word
• orðið = the word
• þetta orð = this word

You do not say þetta orðið in normal standard usage for this meaning.

Yes. It is a very common and useful pattern:

[demonstrative + noun] + er + [predicate noun]

For example:

• Þessi maður er kennari. — This man is a teacher.
• Þetta hús er stórt. — This house is big.
• Þetta orð er nafnorð. — This word is a noun.

So this sentence is simple, natural, and highly typical Icelandic.