Lay brother's not right for late vespers? (7)
I believe the answer is:
placebo
'late vespers?' is the definition.
'placebo' can be an answer for 'vespers?' (placebo is a kind of vespers). I am unsure of the 'late' bit.
'lay brother's not right' is the wordplay.
'lay' becomes 'place' (I can't justify this - if you can you should believe this answer much more).
'brother' becomes 'bro' (short for brother).
'not' indicates named letters should be taken away.
'right' becomes 'r' (common abbreviation).
'bro' with 'r' taken away is 'bo'.
'place'+'bo'='PLACEBO'
'for' is the link.
Can you help me to learn more?
(Other definitions for placebo that I've seen before include "drug for clinical trial" , "Medical treatment whose effect is psychological" , "Medicine that's not" , "Medicine having no physiological effect" , "Medicine given solely for psychological effect" .)