This is the 11649th most frequent German word.
stöger
The word "Stöger" is a German surname and does not have a standalone meaning in standard German vocabulary.
In this sentence, 'stöger' is a colloquial or regional term meaning 'to sift through' or 'examine cursorily'.
Ich stöger gerne durch alte Bücher.
I sift through old books with pleasure.
Here, 'stögerte' is used in the past tense, applying the same colloquial meaning of looking for something.
Max stögerte gestern im Keller nach alten Fotos.
Max sifted through the basement for old photos yesterday.
In this context, 'stögern' indicates the act of searching or sifting through items, and it is presented as a gerund form.