Slight suspicion about entering sauna, say? (6)
I believe the answer is:
breath
'sauna say?' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'slight suspicion about entering' is the wordplay.
'slight suspicion' becomes 'bath' (I can't justify this - if you can you should believe this answer much more).
'about' becomes 're' (common abbreviation for 'with reference to').
'entering' indicates putting letters inside.
'bath' going around 're' is 'BREATH'.
Can you help me to learn more?
(Other definitions for breath that I've seen before include "An inhalation and exhalation" , "It is drawn all the time" , "Air in an out of the lungs" , "Respiration" , "Slight breeze; life" .)