Occasional drinker arrived, then left (5)
I believe the answer is:
camel
'occasional drinker' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'arrived then left' is the wordplay.
'arrived' becomes 'came' ('come' can be a synonym of 'arrive').
'then' says to put letters next to each other.
'left' becomes 'L' (common abbreviation).
'came'+'l'='CAMEL'
Can you help me to learn more?
(Other definitions for camel that I've seen before include "Humped creature" , "Saddle animal in desert regions" , "Bearer of burdens" , "Yellowish" , "It is called the ship of the desert" .)