Strange thing to overdose beside detective, and say thank you? (6)
I believe the answer is:
oddity
'strange thing' is the definition.
(I've seen this in another clue)
'overdose beside detective and say thank you?' is the wordplay.
I cannot really understand how this works, but
'overdose' could be 'od' (synonyms) and 'od' is found within the answer.
'detective' could be 'di' (Detective Inspector abbreviation) and 'di' is found within the answer.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for oddity that I've seen before include "Peculiarity" , "David Bowie's Space ___" , "Something strange or eccentric" , "Toy did (anag.)" , "Quality of strangeness" .)