Das Wörterbuch liegt griffbereit neben dem Laptop, falls ich ein Wort schnell nachschlagen muss.

Yes. liegen literally means to lie or to be lying, but in German it is also very commonly used for objects that are located somewhere.

So:

• Das Wörterbuch liegt neben dem Laptop. = The dictionary is next to the laptop.

In natural English, we often just say is, but German often prefers a more specific verb:

• liegen for things lying flat
• stehen for things standing upright
• hängen for things hanging

So liegt is very normal here.

Griffbereit means within easy reach, close at hand, or readily accessible.

It comes from:

• Griff = grip, grasp
• bereit = ready

So the idea is: the dictionary is close enough that you can grab it immediately.

In the sentence:

• Das Wörterbuch liegt griffbereit neben dem Laptop. = The dictionary is within easy reach next to the laptop.

Because neben can take either the dative or the accusative, depending on whether you are talking about:

• location → dative
• movement toward a place → accusative

Here, the dictionary is already in a position next to the laptop, so this is location:

• neben dem Laptop = next to the laptop

Compare:

• Das Wörterbuch liegt neben dem Laptop. → location, so dative
• Ich lege das Wörterbuch neben den Laptop. → movement/placement, so accusative

Laptop is masculine in German: der Laptop.

Its forms are:

• nominative: der Laptop
• accusative: den Laptop
• dative: dem Laptop

Since neben here expresses location, it takes the dative, so:

• neben dem Laptop

Because Wort is neuter: das Wort.

The article ein changes depending on gender and case. Here, Wort is the direct object of nachschlagen, so it is in the accusative.

For a neuter noun:

• nominative: ein Wort
• accusative: ein Wort

So the form stays the same.

Compare:

• der Tisch → einen Tisch in the accusative
• das Wort → ein Wort in the accusative

Here nachschlagen means to look up, especially in a dictionary, reference book, or similar source.

So:

• ein Wort nachschlagen = to look up a word

This verb can also have other meanings in other contexts, but in this sentence it clearly means look up.

Because the clause begins with falls, which creates a subordinate clause. In German subordinate clauses, the conjugated verb goes to the end.

But here there are actually two verb forms:

• nachschlagen (infinitive)
• muss (conjugated modal verb)

With a modal verb in a subordinate clause, the infinitive comes near the end and the conjugated modal goes at the very end:

• ..., falls ich ein Wort schnell nachschlagen muss.

That is standard German word order.

Because the subject is ich, and the verb must agree with it.

The modal verb müssen is conjugated like this:

• ich muss
• du musst
• er/sie/es muss
• wir müssen
• ihr müsst
• sie/Sie müssen

So:

• ich ... muss = I must / I have to

Falls means in case or if.

In this sentence:

• falls ich ein Wort schnell nachschlagen muss = in case I need to look up a word quickly

It is similar to wenn, but falls often sounds a bit more like in the event that or in case. It can feel slightly more specific or precautionary.

So this sentence suggests:

• the dictionary is there and handy in case the speaker needs it

Schnell is an adverb meaning quickly. It modifies the action nachschlagen.

In German, adverbs often appear before the infinitive or before the verb phrase they modify:

• ein Wort schnell nachschlagen

That means:

• to look up a word quickly

Other placements are sometimes possible depending on emphasis, but this version is very natural.

Yes. Das Wörterbuch is the subject.

You can see this because:

• it is in the nominative
• it is the thing doing the action of liegt

So the main clause is:

• Das Wörterbuch liegt griffbereit neben dem Laptop.

And then the second part is a subordinate clause explaining why that is useful:

• falls ich ein Wort schnell nachschlagen muss

Because Wörterbuch comes from Wörter + Buch.

• das Wort = the word
• die Wörter = the words
• das Buch = the book

So Wörterbuch literally means word book, that is, dictionary.

The ö comes from the plural form Wörter.

Yes. A natural English translation would be something like:

• The dictionary is within easy reach next to the laptop in case I need to look up a word quickly.

A more literal translation would be:

• The dictionary lies close at hand next to the laptop, if I have to look up a word quickly.

The first version is more natural in English, even though the German structure is slightly different.