Principal meets queen in dive (6)
I believe the answer is:
header
'dive' is the definition.
(thesaurus)
'principal meets queen' is the wordplay.
'principal' becomes 'head' ('head' can be a synonym of 'principal').
'meets' says to put letters next to each other.
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'head'+'er'='HEADER'
'in' acts as a link.
(Other definitions for header that I've seen before include "Line at top of each page of a document" , "Lines at top of page" , "Strike of a football" , "Type of dive" , "Text at top of page" .)