Follow measures of the upper-class English (5)
I believe the answer is:
ensue
'follow' is the definition.
(ensue can mean to follow or happen as a result)
'measures of the upper-class english' is the wordplay.
'measures' becomes 'ens' (en is a unit of measurement used by printers).
'of the upper-class' becomes 'U' (as in U- and non-U speech).
'english' becomes 'E' (abbreviation).
'ens'+'u'+'e'='ENSUE'
(Other definitions for ensue that I've seen before include "Follow afterwards" , "Follow subsequently" , "succeed" , "Leading directly to" , "Happen - to come later" .)