Orðabókin hjálpar mér að finna merkingu nýrra orða.

Because -in is the suffixed definite article in Icelandic, so orðabókin means the dictionary.

• orðabók = dictionary
• orðabókin = the dictionary

Icelandic usually adds the to the end of the noun instead of using a separate word like English does.

Orðabókin is in the nominative singular because it is the subject of the sentence — the thing doing the helping.

The verb hjálpar means helps, and the one that helps is the dictionary, so that noun appears in the nominative.

Hjálpar is the present tense, 3rd person singular form of the verb hjálpa (to help).

So:

• ég hjálpa ❌
• ég hjálpa is not correct in standard Icelandic
• ég hjálpaði = I helped
• hann/hún/það hjálpar = he/she/it helps

Here the subject is orðabókin (the dictionary), which is grammatically singular, so the verb is hjálpar.

Because the verb hjálpa takes the dative case, not the accusative.

So:

• mér = to me / me in the dative
• mig = me in the accusative

With hjálpa, Icelandic says:

• hjálpa mér = help me
• hjálpa honum = help him
• hjálpa henni = help her

This is something English speakers usually just have to memorize: hjálpa + dative.

Here að is the infinitive marker, like English to in to find.

So:

• að finna = to find

In this sentence, hjálpar mér að finna ... means helps me to find ... or more naturally in English, helps me find ...

Yes. That is the simplest way to understand it here.

• finna = find
• að finna = to find

After hjálpa, Icelandic commonly uses að + infinitive:

• hjálpa mér að lesa = help me to read
• hjálpa mér að skilja = help me to understand

So this pattern is very useful to learn.

Merkingu is the accusative singular of merking (meaning), because it is the direct object of finna.

You are finding the meaning, so merking has to go into the case required by finna here.

• nominative: merking
• accusative: merkingu

So:

• að finna merkingu = to find a meaning / the meaning

Because Icelandic does not always match English article usage exactly.

In this sentence, merkingu is indefinite in form, even though English often translates it naturally as the meaning.

So Icelandic has:

• merkingu = meaning / sometimes naturally the meaning in context

If you wanted to make it clearly definite in Icelandic, you would use a definite form such as merkinguna.

This is common: sometimes English needs the where Icelandic does not explicitly mark it.

Because nýrra orða is a genitive plural phrase meaning of new words.

Breakdown:

• orð = word
• orða = of words (genitive plural)
• nýrra = of new (genitive plural form of nýr)

So:

• merkingu nýrra orða = the meaning of new words

The noun merking often connects to another noun in the genitive, just like English uses of.

Because after merkingu here, Icelandic uses the genitive to show meaning of something.

So:

• orð = words / word depending on context, but not the right form here
• orða = of words

That is why Icelandic says:

• merking orðs = meaning of a word
• merking orða = meaning of words

In your sentence, it is plural and genitive, so orða is required.

Because adjectives in Icelandic must agree with the noun they describe in case, number, and gender.

Here the noun is:

• orða = genitive plural of orð

So the adjective describing it must also be genitive plural:

• nýrra orða = of new words

This agreement is one of the most important features of Icelandic grammar.

The structure is:

• Orðabókin = subject
• hjálpar = verb
• mér = indirect object / dative object
• að finna = infinitive phrase
• merkingu nýrra orða = object of the infinitive, with a genitive phrase attached

So literally it is something like:

• The dictionary helps me to find meaning of new words

More natural English:

• The dictionary helps me find the meaning of new words.

Because Icelandic is generally a verb-second (V2) language in main clauses.

In this sentence, the subject comes first:

• Orðabókin = first element

So the finite verb comes next:

• hjálpar

That gives:

• Orðabókin hjálpar ...

This is very normal Icelandic word order.

The nouns are:

• orðabók = feminine
• merking = feminine
• orð = neuter

This matters because gender affects articles, adjective forms, and case endings.

For example:

• orðabókin has the feminine definite ending
• nýrra agrees with orða in case/number, and in this form the genitive plural happens to look the same across genders

It would become singular:

• merkingu nýs orðs

Breakdown:

• nýs = genitive singular of nýr
• orðs = genitive singular of orð

So:

• merkingu nýs orðs = the meaning of a new word

This is a useful comparison with your original phrase:

• merkingu nýrra orða = meaning of new words
• merkingu nýs orðs = meaning of a new word

Yes, it is natural and idiomatic.

A learner can use it as a good model for several common patterns:

• definite noun with suffixed article: orðabókin
• hjálpa + dative: hjálpar mér
• að + infinitive: að finna
• noun + genitive phrase: merkingu nýrra orða

So it is a very useful sentence for learning everyday Icelandic grammar.