After experiences, twelve on vacation with expedition (9)
I believe the answer is:
posthaste
'expedition' is the definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?
'after experiences twelve on vacation' is the wordplay.
'after' becomes 'post' (prefix meaning after, eg post-war).
'experiences' becomes 'has' (have can mean to experience or go through).
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'twelve' with its centre taken out is 'te'.
'post'+'has'+'te'='POSTHASTE'
'with' is the link.
Can you help me to learn more?
(Other definitions for posthaste that I've seen before include "Express" , "Like Bat out of Hell" , "Speedily" , "As quickly as possible" , "at the double" .)