The most common and most likely answer to this crossword clue is the 8 letter word SUBJECTS
I've seen this crossword clue in The Sunday Telegraph
S
U
B
J
E
C
T
S
More clues leading to the result SUBJECTS
- People of the UK maybe in History and Geography, for example
- We, for example, are also citizens
- Disciplines citizens
- Issues for people ruled by a monarch
- Monarchs have these things to discuss
- Citizens taught in schools
- Points to vehicle knocked over by planes travelling around speed of light
- Queen’s given these topics
Buddy explains!

The straight part
We know that "Disciplines/citizens" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case disciplines/citizens = subjects.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SUBJECTS mean?
SUBJECTS noun- (grammar) In a clause: the word or word group (usually a noun phrase) that is dealt with. In active clauses with verbs denoting an action, the subject and the actor are usually the same.
- An actor; one who takes action.
- The main topic of a paper, work of art, discussion, field of study, etc.
- A particular area of study.
- A citizen in a monarchy.
- A person ruled over by another, especially a monarch or state authority.
- The main theme or melody, especially in a fugue.
- A human, animal or an inanimate object that is being examined, treated, analysed, etc.
- A being that has subjective experiences, subjective consciousness, or a relationship with another entity.
- That of which something is stated.
- The variable in terms of which an expression is defined.
- (construed with to) To cause (someone or something) to undergo a particular experience, especially one that is unpleasant or unwanted.
- To make subordinate or subservient; to subdue or enslave.