Something that is outdated or no longer interesting.

An idea or opinion that is no longer novel or exciting.

एक विचार या राय जो अब नई या रोमांचक नहीं है

English Usage: His approach to solving problems was considered old hat by his colleagues.

Hindi Usage: समस्याओं को हल करने का उसका तरीका उसके सहयोगियों द्वारा पुराना माना गया।