nachholen
to make up
To do, experience, or compensate for something at a later time that one missed or failed to do.
Da er krank war, muss er die Klassenarbeit nächste Woche nachholen.
Since he was sick, he has to make up the class test next week.

to make up
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to make up
To do, experience, or compensate for something at a later time that one missed or failed to do.
Da er krank war, muss er die Klassenarbeit nächste Woche nachholen.
Since he was sick, he has to make up the class test next week.

'Nachholen' (to make up) is a separable verb. The prefix 'nach-' goes at the end in main clauses. In subordinate clauses and in the infinitive, the verb stays together.
Ich hole den verpassten Unterrichtsstoff am Wochenende nach.
I will make up the missed lesson material over the weekend.
The verb is made up of the prefix 'nach-' (later, afterward) and 'holen' (to fetch/get). The meaning is therefore logical: you 'get' something you missed at a later time.
Wir müssen unser Treffen unbedingt bald nachholen.
We absolutely have to make up our meeting soon.
You can make up many different things. Common combinations are: 'Schlaf nachholen' (to catch up on sleep), 'eine Prüfung nachholen' (to make up an exam), 'einen Termin nachholen' (to make up an appointment), 'den Urlaub nachholen' (to make up for a vacation), or 'Hausaufgaben nachholen' (to make up homework).
Nach der anstrengenden Woche muss ich am Wochenende dringend Schlaf nachholen.
After the exhausting week, I urgently need to catch up on sleep over the weekend.
to miss / to give
'verpassen' and 'nachholen' are clear opposites in terms of time. 'verpassen' is used when you do not experience, reach, or do something in time. 'nachholen' is used afterward, when you still do the missed thing later or make up for it. The words can be confused because they often talk about the same thing: for example, you miss a lesson and make it up later. Memory tip: first you miss something, then you can make it up.

Der Gast hat die Sendung verpasst, aber er holt sie am Abend nach.
The guest missed the program, but he is making it up in the evening.
Am Montag verpasst du in der Schule den Film über den Wald.
On Monday, you will miss the film about the forest at school.