Poke single lass getting reckless (8)
I believe the answer is:
prodigal
'reckless' is the definition.
(thesaurus)
'poke single lass getting' is the wordplay.
'poke' becomes 'prod' ('prod' can be a synonym of 'poke'**).
'single' becomes 'i' (one).
'lass' becomes 'gal' (I've seen this before).
'getting' says to put letters next to each other.
'prod'+'i'+'gal'='PRODIGAL'
(Other definitions for prodigal that I've seen before include "Wasting money" , "Spendthrift" , "overspending" , "Extravagant like Biblical son" , "Squandering" .)