Hinders second examiner's case, cutting corners (8)

'hinders' is the definition.
(to snooker someone is to frustrate or block them)

'second examiner's case cutting corners' is the wordplay.
'second' becomes 's' (common abbreviation).
'case' says to hollow out the word (remove centre letters).
'cutting' indicates putting letters inside (some letters cut their way into a word).
'corners' becomes 'nooks' ('nook' can be a synonym of 'corner').
'examiner' with its middle removed is 'er'.
'er' put inside 'nooks' is 'nookers'.
's'+'nookers'='SNOOKERS'