Jocularity of learner in class of lowly types (10)
I believe the answer is:
pleasantry
'jocularity' is the definition.
(I know that pleasantry is a type of jocularity)
'learner in class of lowly types' is the wordplay.
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'in' indicates putting letters inside.
'class of lowly types' becomes 'peasantry' (people of low social position).
'l' put within 'peasantry' is 'PLEASANTRY'.
'of' is the link.
(Other definitions for pleasantry that I've seen before include "Jocular comment" , "Slightly amusing remark" , "An agreeable remark" , "Say, how are you doing" , "Sally" .)