Το σύνθημα εισόδου είναι στο θεατρικό κείμενο.

Because σύνθημα is a neuter singular noun, and το is the neuter singular definite article in the nominative.

So:

• το σύνθημα = the password / the slogan / the code word

A very common pattern in Greek is:

• ο for masculine nouns
• η for feminine nouns
• το for neuter nouns

Since σύνθημα is neuter, it takes το.

Here σύνθημα is in the nominative singular because it is the subject of the verb είναι.

The basic structure is:

• Το σύνθημα εισόδου = the subject
• είναι = is
• στο θεατρικό κείμενο = in the theatrical text / in the script

Also, many neuter nouns ending in -μα are common in Greek, for example:

• το γράμμα
• το όνομα
• το πρόβλημα
• το σύνθημα

Because εισόδου is the genitive singular form of η είσοδος.

So:

• η είσοδος = entrance / entry / access
• της εισόδου = of the entrance / of entry / of access
• εισόδου in σύνθημα εισόδου works like entry password, access code, or login password

This is a very common Greek pattern: one noun modifies another by using the genitive.

So:

• σύνθημα εισόδου literally = password of entry/access
• natural English = login password or access code, depending on context

Because Greek often uses a bare genitive noun in expressions like this, especially when the second noun functions almost like a label or category.

So σύνθημα εισόδου is a natural compact phrase, similar to:

• κωδικός ασφαλείας = security code
• πόρτα εξόδου = exit door
• χάρτης πόλης = city map

If you added an article, such as της εισόδου, the phrase would sound more specifically like the password of the entrance/access, which may change the nuance and often sounds less like a fixed expression.

είναι is the third person singular form of είμαι, meaning to be.

Here it means is, because the subject το σύνθημα εισόδου is singular.

So:

• είμαι = I am
• είσαι = you are
• είναι = he/she/it is, or they are in some contexts

In this sentence:

• Το σύνθημα εισόδου είναι... = The login password is...

στο is a contraction of:

• σε = in / at / to
• το = the

So:

• σε το becomes στο

This is extremely common in Modern Greek.

Other similar contractions are:

• σε + τον = στον
• σε + την = στην
• σε + τους = στους
• σε + τις = στις

So στο θεατρικό κείμενο means in the theatrical text / in the play script.

Because θεατρικό is an adjective, and it must agree with κείμενο in gender, number, and case.

Since κείμενο is:

• neuter
• singular

the adjective must also be:

• neuter singular

So:

• θεατρικός = masculine
• θεατρική = feminine
• θεατρικό = neuter

That is why Greek says:

• το θεατρικό κείμενο

Grammatically, after σε, Greek uses the accusative.

So in στο θεατρικό κείμενο, κείμενο is accusative singular.

However, for many neuter singular nouns, the nominative and accusative forms are identical. That is why it looks the same as the dictionary form.

So:

• nominative: το κείμενο
• accusative: το κείμενο

Same form, different grammatical role.

Yes. Greek word order is often more flexible than English word order.

The neutral order here is:

• Το σύνθημα εισόδου είναι στο θεατρικό κείμενο.

But Greek could also move things around for emphasis, for example:

• Στο θεατρικό κείμενο είναι το σύνθημα εισόδου.

That version puts more focus on where the password is.

Even so, the original version is very natural and straightforward.

A rough pronunciation guide is:

to SEEN-thee-ma ee-SO-thoo EE-ne sto the-a-tree-KO KEE-me-no

A few helpful points:

• σύνθημα is stressed on σύν
• εισόδου is stressed on σό
• είναι is stressed on εί
• θεατρικό is stressed on κό
• κείμενο is stressed on κεί

Also:

• θ sounds like the th in think
• δ sounds like the th in this
• ει is pronounced like ee

No. σύνθημα can mean different things depending on context, such as:

• slogan
• motto
• watchword
• password
• code word

So the exact English translation depends on the situation.

In a technical or access-related context, σύνθημα εισόδου is naturally understood as something like:

• login password
• access password

In a political or social context, σύνθημα might instead mean slogan.