A new teacher, initially hot and sick, finding mound (7)
I believe the answer is:
anthill
'mound' is the definition.
(anthill is a kind of mound)
'a new teacher initially hot and sick' is the wordplay.
'initially' suggests taking the first letters.
'hot' becomes 'h' (abbreviation eg on taps).
'and' says to put letters next to each other.
'sick' becomes 'ill' (synonyms).
The first letters of 'new teacher' is 'nt'.
'a'+'nt'+'h'+'ill'='ANTHILL'
'finding' is the link.
(Other definitions for anthill that I've seen before include "Mound of insects" , "There's much work to be done here" , "Mountain (of insects)" , "Home to thousands" , "Many a worker here" .)