Former spouse wasted a tiny period making a journey (13)
I believe the answer is:
expeditionary
'making a journey' is the definition.
I can't tell whether this defines the answer.
'former spouse wasted a tiny period' is the wordplay.
'former spouse' becomes 'ex' (an ex-spouse).
'wasted' is an anagram indicator.
'a'+'tiny'+'period'='atinyperiod'
'atinyperiod' with letters rearranged gives 'peditionary'.
'ex'+'peditionary'='EXPEDITIONARY'
Can you help me to learn more?
(Another definition for expeditionary that I've seen is " Of a purposeful journey".)