Leave behind great trouble on holiday, for starters (7)
I believe the answer is:
outgrow
'leave behind' is the definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Maybe there's a link between them I don't understand?
'great trouble on holiday for starters' is the wordplay.
I cannot quite see how this works, but
'great' could be 'gr' and 'gr' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for outgrow that I've seen before include "Develop faster or become taller than" , "Become too big for" , "Leave (something) behind as one matures" , "Get too big for" , "Develop beyond" .)