Reminder for musician on vacation on irregular income (8)
I believe the answer is:
mnemonic
'reminder' is the definition.
(I've seen this before)
'musician on vacation on irregular income' is the wordplay.
'on vacation' suggests removing the centre (after the inside letters have vacated the word).
'on' is a charade indicator (letters next to each other).
'irregular' indicates an anagram.
'musician' with its centre removed is 'mn'.
'income' with letters rearranged gives 'emonic'.
'mn'+'emonic'='MNEMONIC'
'for' acts as a link.
(Other definitions for mnemonic that I've seen before include "Device for remembering things" , "It reminds us" , "Phrase devised to assist memory" , "System for improving memory" , "Device (such as an acronym) used to aid recall" .)