Lack of reverence from naughty child that is teary on vacation (7)
I believe the answer is:
impiety
'lack of reverence' is the definition.
(I've seen this before)
'naughty child that is teary on vacation' is the wordplay.
'naughty child' becomes 'imp' (informal term for a misbehaving child).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'on vacation' says to hollow out the word (remove centre letters).
'teary' with its middle taken out is 'ty'.
'imp'+'ie'+'ty'='IMPIETY'
'from' acts as a link.
(Other definitions for impiety that I've seen before include "Irreligion" , "godlessness" , "Irreverence, profanity" , "Lack of reverence" , "sacrilege" .)