Yes. The clues "synonyms" is about the meaning(s) of the word(s) and not the spelling or sound of the word(s) or position(s) on the board or anything else other than the meaning(s) of the word(s).
Yes, it's a stretch, perhaps, but most clues are .
The point is that it adheres to / doesn't violate any of the "firm rules" ...
From the rules:-
DON'T BE TOO STRICT
If the opposing spymaster allows it, the clue is valid.
Sometimes you have to make judgment calls about what is valid and what
is not. Different groups may prefer to play the game differently.
For any question about if a clue is a valid all the above applies. Unless there is a rule which prohibits a clue ...
Codenames enjoys a variety of flexible rules and often it's up to the opposing spymaster to allow cases like this. 9/11 could definitely fit in either of the following 2 flexible rules, but since they are flexible rules, it's best left to the group to decide if it's allowed or not.
While technically wildly different, 9/11 is not just a date, but it's the ...
Just as the rules say your group might agree to treat "New York" as a word, even though it is two words and therefore not allowed by the stock rules (and so the topic would need to be brought up and agreed upon before the game), your group might agree to allow numbers ("nine hundred and eleven") as words, even though some numbers are more ...
If it's one English word and it's a clue about the meaning(s) of the word(s) on the table (and it isn't a form of any words on the table, etc.), then it's a valid clue, yes. Apostrophes are not prohibited.
(Not rule to cite; it is difficult to prove a negative).
For the question of "women's" vs. "woman's", etc., you are free to spell it ...
No. First entry under "Firm Rules"
Your clue must be about the meaning of the words. You can't use your clue to talk about the letters in a word or its position on the table.
I agree with a comment on another answer to keep the firm rule in place; as position clues can be used on every board, the game will become repetitive if they're allowed.
From the Codenames rule book:
Your clue must be about the meaning of the
words. You can't use your clue to talk about
the letters in a word or its position on the table.
This rule is in place to keep the game interesting.
I would recommend keeping close to the game rules, but if the spymaster thinks they've got the perfect clue (Maybe there are two ...