The word "subject" can refer to several different concepts, but generally, it means a person or thing that is being discussed, described, or dealt with. In academic contexts, it often refers to a specific area of study, such as mathematics or history. Additionally, it can also mean to cause someone to undergo or experience something, especially something unpleasant or challenging.
The word "subject" comes from the Latin "subiectus," which means "lying under, placed under." It is derived from "sub-" meaning "under" and "iacere" meaning "to throw." This origin denotes the concept of something being placed under discussion or consideration.