Osušit ću kosu fenom prije sastanka.

It is the future tense and means I will dry.

Croatian future tense is often made with:

• the infinitive of the verb
• plus a short form of htjeti: ću, ćeš, će, ćemo, ćete, će

So from osušiti = to dry / to dry completely, you get:

• ja ću osušiti = I will dry
• osušit ću = I will dry

When the infinitive comes before the clitic ću, the final -i of the infinitive is usually dropped in writing:

• osušiti + ću → osušit ću

So osušit ću is completely normal Croatian.

Because Croatian usually omits subject pronouns when they are already clear from the verb form.

In ću, the speaker is already understood to be I:

• (Ja) ću = I will

So:

• Osušit ću kosu fenom prije sastanka. naturally means:
• I’ll dry my hair with a hairdryer before the meeting.

You can add ja for emphasis:

• Ja ću osušiti kosu prije sastanka. This sounds more like I will dry my hair, maybe contrasting with someone else.

Because kosa is the nominative form, but here the word is the direct object of the verb osušiti.

The direct object usually goes in the accusative, so:

• kosa = hair
• kosu = hair, as the object

This is a very common pattern for feminine nouns ending in -a:

• nominative singular: -a
• accusative singular: -u

So:

• Imam dugu kosu. = I have long hair.
• Sušim kosu. = I am drying my hair.

Croatian often leaves out possessive words like my when the meaning is obvious, especially with body parts and things closely associated with the person.

So:

• Osušit ću kosu. very naturally means
• I will dry my hair.

If you want to be more explicit, you could say:

• Osušit ću svoju kosu. But that often sounds unnecessary unless you are emphasizing that it is your own hair, not someone else’s.

You may also hear:

• Osušit ću si kosu. Here si adds the idea for myself / my own and is very common in everyday speech.

Fenom is the instrumental singular of fen.

It is used here because Croatian often uses the instrumental to express the tool or means used to do something:

• fen = hairdryer
• fenom = with a hairdryer / using a hairdryer

So:

• Osušit ću kosu fenom. = I will dry my hair with a hairdryer.

This is similar to:

• Pišem olovkom. = I write with a pencil.
• Režem nožem. = I cut with a knife.

Also, fen is a very common everyday word. A more formal term is sušilo za kosu.

Prije means before, and it requires the genitive case.

So:

• sastanak = meeting
• sastanka = of the meeting / before the meeting, after prije

That is why the sentence has:

• prije sastanka = before the meeting

Other examples:

• prije ručka = before lunch
• prije škole = before school
• prije puta = before the trip

So the pattern is:

• prije + genitive

This is a question of aspect, which is very important in Croatian.

• sušiti = imperfective, focusing on the process or repeated action
• osušiti = perfective, focusing on completing the action

So:

• Sušim kosu. = I am drying my hair.
• Osušit ću kosu. = I will dry my hair completely / I’ll get it dry.

In this sentence, osušit ću is used because the idea is that the action will be finished before the meeting.

Yes. Croatian word order is fairly flexible, though not completely free. The basic meaning stays the same, but the emphasis can change.

These are all possible:

• Osušit ću kosu fenom prije sastanka.
• Ja ću osušiti kosu fenom prije sastanka.
• Kosu ću osušiti fenom prije sastanka.
• Prije sastanka ću osušiti kosu fenom.

The sentence you were given is very natural. Starting with osušit ću gives a smooth, conversational feel.

One important point: the short auxiliary ću behaves like a clitic, so its position is restricted. That is one reason Croatian word order has rules even though it is flexible.

In standard Croatian, if the infinitive comes directly before ću, the usual written form is:

• osušit ću

not:

• osušiti ću

But if the auxiliary comes first, then you keep the full infinitive:

• Ja ću osušiti kosu.

So the standard pattern is:

• ću + infinitive → ću osušiti
• infinitive + ću → osušit ću

Yes, fen is very common in everyday speech and perfectly natural in this sentence.

You may also see or hear:

• sušilo za kosu = hairdryer

The difference is mostly style:

• fen = shorter, everyday, very common
• sušilo za kosu = more formal or descriptive

So:

• Osušit ću kosu fenom. sounds natural and idiomatic.