Features of ill-meant boring punishment at school (10)

'features' is the definition.
('lineament' can be a synonym of 'feature')

'ill-meant boring punishment at school' is the wordplay.
'ill' indicates an anagram.
'boring' indicates putting letters inside (some letters must 'bore' a hole into other letters).
'punishment at school' becomes 'lines'.
'meant' anagrammed gives 'ament'.
'ament' going into 'lines' is 'LINEAMENTS'.

'of' is the link.