الاجتماع الليلة.

Because Arabic often leaves out the verb to be in the present tense.

So الاجتماع الليلة literally looks like the meeting tonight, but it naturally means The meeting is tonight.

This is very normal in both Standard Arabic and Levantine-style sentences:

• هو تعبان = He is tired
• البيت كبير = The house is big
• الاجتماع الليلة = The meeting is tonight

If you wanted a past or future meaning, then Arabic would usually use a verb:

• كان الاجتماع مبارح = The meeting was yesterday
• الاجتماع رح يكون الليلة = The meeting will be tonight

A natural Levantine-style pronunciation would be roughly:

il-ijtimāʿ il-lēle

A few notes:

• الاجتماع → il-ijtimāʿ
• الليلة → il-lēle
• The final ع in اجتماع is the consonant ʿayn, which English does not have.

If you are not comfortable with ʿayn yet, that is very common for learners. It is still worth noticing that ijtimāʿ does not end like a normal English vowel sound.

الاجتماع means the meeting.

It comes from the root ج م ع, which has the basic idea of gathering or bringing together. So اجتماع is literally something like a gathering / meeting.

The ال at the beginning is the, so:

• اجتماع = a meeting
• الاجتماع = the meeting

In this sentence, الليلة means tonight.

Even though it literally looks like the night, Arabic often uses this definite form to mean tonight / this evening, depending on context.

So:

• ليلة = a night
• الليلة = tonight / this night

In Levantine, الليلة is a very common way to say tonight. Another common colloquial option is:

• اليوم بالليل = tonight / today at night

Because the ل in ليلة is a sun letter.

In Arabic, when ال comes before a sun letter, the l of the article blends into the first consonant of the word, and that consonant gets doubled in pronunciation.

So:

• written: الليلة
• pronounced: il-lēle

You see the article in writing, but in speech the l sound is strengthened.

This is the same idea in words like:

• الشمس → pronounced ish-shams
• الناس → pronounced in-nās

The spelling is completely normal Arabic and is easy to understand in both Standard Arabic and Levantine.

A few things to keep in mind:

• The written form الاجتماع الليلة looks quite neutral and could appear in MSA or in writing generally.
• In Levantine speech, the pronunciation would be different from formal MSA pronunciation.
• In everyday conversation, a speaker might also choose a more obviously colloquial phrasing, depending on region and situation.

So the sentence is perfectly understandable for a Levantine learner, even if it is not marked with strongly dialect-specific spelling.

Yes.

Without more context, Arabic can leave this a little open. It can be understood as:

• a full verbless sentence: The meeting is tonight
• a noun phrase: the meeting tonight

For example:

• On a schedule or reminder, it might feel like a heading: The meeting tonight
• In conversation, it very naturally means: The meeting is tonight

So context tells you whether it is being used as a complete sentence or just a phrase.

They are definite for different reasons.

• الاجتماع is definite because it refers to a specific meeting: the meeting
• الليلة is definite because Arabic commonly uses this form to mean tonight

So this is not unusual. Arabic often uses definite forms in time expressions:

• اليوم = today
• الليلة = tonight
• الصبح in some dialect contexts = in the morning

English and Arabic do not always match exactly in how they use the.

Yes, depending on the speaker and region.

Possible everyday alternatives include:

• الاجتماع الليلة
• الاجتماع اليوم بالليل

Both can work for The meeting is tonight.

The first one is shorter and very common. The second one can feel a little more explicitly colloquial to some learners because it literally says today at night.

Yes. Arabic allows some flexibility.

For example:

• الاجتماع الليلة = The meeting is tonight
• الليلة الاجتماع = Tonight is the meeting / The meeting is tonight

The second version gives more emphasis to tonight. In normal neutral speech, الاجتماع الليلة is a very straightforward choice.

A common Levantine way would be:

• الاجتماع مش الليلة
• الاجتماع مو الليلة

That means The meeting isn’t tonight.

Which negative particle sounds more natural depends on the region:

• مش is very common in many areas
• مو is also common in many Levantine varieties

So this sentence is a good example of how Arabic handles present-tense meaning without using is, and then uses a negative particle when you want to deny it.