English politician experiences one's stress (8)
I believe the answer is:
emphasis
'stress' is the definition.
(I know that stress can be written as emphasis)
'english politician experiences one's' is the wordplay.
'english' becomes 'E' (abbreviation).
'politician' becomes 'MP' (Member of Parliament).
'experiences' becomes 'has' (have can mean to experience or go through).
'one's' becomes 'i's' (Roman numeral).
'e'+'mp'+'has'+'is'='EMPHASIS'
(Other definitions for emphasis that I've seen before include "Stress - misshape (anag)" , "Stress given to a word" , "Accentutation" , "Stress or significance" , "Stress, accentuation" .)