Origin: Latin prefix sub-
Subject has 17 different meanings across 3 categories:
something (a person or object or scene) selected by an artist or photographer for graphic representation
"a moving picture of a train is more dramatic than a still picture of the same subject"
a branch of knowledge
"in what discipline is his doctorate?"
"teachers should be well trained in their subject"
"anthropology is the study of human beings"
(grammar) one of the two main constituents of a sentence; the grammatical constituent about which something is predicated
"In the phrase "The cat sleeps," the word "cat" functions as the subject because it is what the verb describes."
a person who is subjected to experimental or other observational procedures; someone who is an object of investigation
"the subjects for this investigation were selected randomly"
"the cases that we studied were drawn from two different communities"
(logic) the first term of a proposition
"In his syllogism, Socrates is the subject that serves as the starting point for the entire logical argument."
In a clause: the word or word group (usually a noun phrase) about whom the statement is made. In active clauses with verbs denoting an action, the subject and the actor are usually the same.
"In the sentence "The cat chased the mouse," the word "cat" functions as the subject because it is both the topic of the statement and the one performing the chasing action."
In plain English: A subject is the main person, place, or thing that an action happens to or that a statement is about.
"The teacher asked us to pick a subject for our history project."
Usage: Use this term specifically in grammar to identify the person or thing performing an action or being described by the verb; avoid confusing it with "topic," which refers broadly to what a text is about regardless of grammatical structure. Remember that while active sentences typically align the subject and actor, passive constructions separate them entirely.
cause to experience or suffer or make liable or vulnerable to
"He subjected me to his awful poetry"
"The sergeant subjected the new recruits to many drills"
"People in Chernobyl were subjected to radiation"
To cause (someone or something) to undergo a particular experience, especially one that is unpleasant or unwanted.
"The sudden power outage subjected everyone in the building to thirty minutes of freezing darkness and panic."
In plain English: To be the person or thing that is doing the action in a sentence.
"The teacher will subject us to a surprise quiz tomorrow."
likely to be affected by something
"the bond is subject to taxation"
"he is subject to fits of depression"
Likely to be affected by or to experience something.
"After months of intense training, his body was finally ready, making him no longer a subject for injury."
In plain English: Subject means being the main topic of discussion or attention.
"The teacher asked all the students to submit their subject homework by Friday."
The word "subject" comes from the Latin subiectus, meaning "lying under," which was originally used to describe someone in an inferior position or something placed beneath another. It entered English via Old French and Ancient Greek, where it carried meanings ranging from a political subject to the topic of a discussion.