What may be diagnosed by doctor initially poking tongue? (6)
I believe the answer is:
malady
'what may be diagnosed' is the definition.
'doctor initially poking tongue?' is the wordplay.
'initially' indicates taking the first letters.
'poking' means one lot of letters goes inside another (poke can mean to create a hole in).
'tongue?' becomes 'malay' ('tongue' can mean a language).
The first letter of 'doctor' is 'd'.
'd' put inside 'malay' is 'MALADY'.
'by' is the link.
(Other definitions for malady that I've seen before include "Disease, ailment" , "Afflication" , "Illness or disease" , "Sickness or disease" , "Disease or disorder" .)