This is the 326th most frequent Russian word.
которым
"Которым" means "which" or "whom" in the instrumental or dative case.
The word 'которым' ('by which') is used as a relative pronoun in the instrumental case, matching the noun 'подарок' ('gift') and aligning with the verb 'удивлен' ('surprised by').
Это подарок, которым я был удивлен.
This is a gift by which I was surprised.
The word 'которым' ('that') acts as a relative pronoun referring to 'город' ('city') in the instrumental case, required by the verb 'хвалится' ('boasts about').
Мы посетили город, которым он часто хвалится.
We visited the city that he often boasts about.
The word 'которым' ('whom') functions as a relative pronoun referring to 'человека' ('person') in the instrumental case, as required by the verb 'восхищаюсь' ('admire').