Scruffy graduate teacher teased about student (10)
I believe the answer is:
bedraggled
'scruffy' is the definition.
(thesaurus)
'graduate teacher teased about student' is the wordplay.
'graduate teacher' becomes 'bed' (BEd - holder of Bachelor of Education degree).
'teased' becomes 'ragged' ('rag' can be a synonym of 'tease').
'about' means one lot of letters goes inside another.
'student' becomes 'l' (as in L-plates for learner drivers).
'ragged' enclosing 'l' is 'raggled'.
'bed'+'raggled'='BEDRAGGLED'
(Other definitions for bedraggled that I've seen before include "Unkempt" , "muddy and dripping" , "Very untidy" , "Dishevelled" , "Wet and dirty" .)