Meaning of subject in English
1. the person or thing that is being discussed or dealt with in a conversation or a book; topic or theme
The subject of the picture is "Sun".
2. an area of knowledge that you study at school or university; discipline
What is your favorite subject?
3. a person who lives under the rule of a government; citizen or national
4. the person or thing that is doing the action of the verb, for example, ‘Tom’ in the sentence, Tom is studying Russian at school.