A letter from Ruby at the massage parlour? (3)
I believe the answer is:
rub
'the massage parlour?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'a letter from ruby' is the wordplay.
'a letter' becomes 'y' (Y is a letter of the alphabet).
'from' indicates named letters should be taken away.
'ruby' with 'y' removed is 'RUB'.
'at' acts as a link.
Can you help me to learn more?
(Other definitions for rub that I've seen before include "Chafe; difficulty" , "Abrade" , "Cause friction" , "Advice to Aladdin" , "trouble" .)