This is the 580th most frequent Azerbaijani word.
birində
"Birində" in English means "in one of them."
In this sentence, 'birində' denotes 'in one (person, entity) among' referring to one friend from a group.
Dostlarımın birində əla bir fikir var idi.
One of my friends had a great idea.
Here, 'birində' means 'in one of' a set of events (parties) indicating a specific occurrence within a group.
Partiyalardan birində çox adam iştirak etdi.
A lot of people attended one of the parties.
Here, 'birində' refers to 'in one of' specifying one among several.