As a Noun: 1. The study or creation of theories about basic things such as the nature of existence or how people should live; or a particular set of such ideas. English = philosophy. 2. A person who is concerned with the study or creation of theories about basic things such as the nature of existence or how people should live. English = philosopher. As a Verb or Adjective: 1. To study or create theories about basic things such as the nature of existence or how people should live. English = do philosophy, study philosophy. 2. To talk or write about basic, important subjects such as life, often in a boring, pretentious way. English = philosophise. 3. To be concerned with or to relate to philosophy; or, more generally, to have a wise and accepting attitude to misfortune and suffering in life. English = (be) philosophical.