Characters in southeasterly hostel taken out on the Thames, speaking this kind of English (7)
I believe the answer is:
estuary
'the thames speaking this kind of english' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'characters in southeasterly hostel taken out' is the wordplay.
'characters in' is an anagram indicator.
'taken out' is a deletion indicator.
'southeasterly' with 'hostel' taken away is 'uastery'.
'uastery' with letters rearranged gives 'ESTUARY'.
'on' acts as a link.
Can you help me to learn more?
(Other definitions for estuary that I've seen before include "Bristol Channel?" , "Inlet of sea" , "should be apparent at Dartmouth?" , "River outlet" , "Wide river-mouth" .)