Soothe everyone English through endless tea (9)
I believe the answer is:
alleviate
'soothe' is the definition.
(I've seen this before)
'everyone english through endless tea' is the wordplay.
'everyone' becomes 'all' (all people).
'english' becomes 'e' (abbreviation).
'through' becomes 'via' (I've seen this before).
'endless' means to remove the last letter.
'tea' with its last letter taken off is 'te'.
'all'+'e'+'via'+'te'='ALLEVIATE'
(Other definitions for alleviate that I've seen before include "Make less severe, say suffering" , "Assuage" , "Make light" , "moderate" , "Make (suffering etc) easier to bear" .)