festgelegt
fixed
Bindingly determined, defined, or decided. Describes something that can no longer be changed, or only with difficulty.
Der Termin für die Prüfung ist bereits festgelegt.
The date for the exam has already been fixed.

fixed / determined
Loading your saved state.
fixed
Bindingly determined, defined, or decided. Describes something that can no longer be changed, or only with difficulty.
Der Termin für die Prüfung ist bereits festgelegt.
The date for the exam has already been fixed.

'Festgelegt' (fixed/determined) is the past participle of the separable verb 'festlegen' (to determine/fix). It consists of 'fest' (fixed/firm) and 'legen' (to lay) and literally means to lay something down so that it is fixed and no longer moves.
Wir müssen die Regeln für das Projekt genau festlegen.
We have to define the rules for the project precisely.
Since 'festlegen' (to determine/fix) is a separable verb, the prefix 'fest-' comes at the end in a main clause. However, the participle 'festgelegt' (fixed/determined) is always written as one word.
Die Firma legt die neuen Preise fest.
The company fixes the new prices.
Typical things that are 'festgelegt' (fixed/determined) are appointments, deadlines, rules, prices, goals, or an exact date.
Die Route für den Marathon ist jetzt endgültig festgelegt.
The route for the marathon is now finally fixed.
The expression 'sich festgelegt haben' (to have decided/committed oneself) means that a person has made a personal decision. It is always formed with a reflexive pronoun (mich, dich, sich, etc.).
Er hat sich schon für ein Studienfach festgelegt.
He has already decided on a field of study.
When you want to say what you have decided on, you use the preposition 'auf' followed by the accusative.
Sie hat sich auf ein Thema für ihre Masterarbeit festgelegt.
She has decided on a topic for her master's thesis.
certain / specific
'bestimmt' and 'festgelegt' can both express that something is not arbitrary. 'bestimmt' often simply means a specific thing or an intended purpose, for example 'ein bestimmter Tag' (a specific day) or a room that is 'für Gäste bestimmt' (intended for guests). 'festgelegt' means more strongly that something has been decided or regulated in a binding way. It then cannot be changed easily. Learners may confuse the words because both have to do with a choice or decision. If you only mean something specific, 'bestimmt' fits. If a decision is official or binding, 'festgelegt' is better.

Der Termin für die Prüfung ist jetzt festgelegt.
The date for the exam has now been fixed.
Für diese Aufgabe brauchen wir ein bestimmtes Formular.
We need a specific form for this task.