Woman takes school lessons in speech (9)
I believe the answer is:
discourse
'speech' is the definition.
(discourse is a kind of speech)
'woman takes school lessons' is the wordplay.
'woman' becomes 'Di' (short for Diana).
'takes' says to put letters next to each other.
'school' becomes 'S'.
'lessons' becomes 'course' (a course has lessons).
'di'+'s'+'course'='DISCOURSE'
'in' is the link.
(Other definitions for discourse that I've seen before include "(Formal) talk" , "Speech - conversation" , "Formal discussion of a topic" , "Conversation, dialogue" , "verbal communication" .)