This is the 8972nd most frequent Catalan word.
extrem
"Extrem" in Catalan means "extreme" or "end."
Here, 'extrem' is used as a noun referring to the farthest point or edge of something.
El cim de la muntanya és un extrem preciós del paisatge.
The summit of the mountain is a beautiful extremity of the landscape.
In this case, 'extremament' is an adverb derived from 'extrem', modifying the adjective to mean 'to a very high degree'.
És extremament important escoltar amb atenció durant la reunió.
It is extremely important to listen carefully during the meeting.
Here, 'extrem' functions as an adjective describing the intensity or extent of someone's behavior.