Cheap informal English comedian entertaining small number (8)
I believe the answer is:
economic
'cheap' is the definition.
(I've seen this before)
'english comedian entertaining small number' is the wordplay.
'english' becomes 'E' (abbreviation).
'comedian' becomes 'comic' (synonyms).
'entertaining' is an insertion indicator (inviting in, as for dinner).
'small number' becomes 'no' (abbreviation; 'small' suggests an abbreviation).
'comic' enclosing 'no' is 'conomic'.
'e'+'conomic'='ECONOMIC'
'informal' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for economic that I've seen before include "system of money" , "Sparing with resources or money" , "Fiscal" , "Likely to bring a profit" , "Relating to careful financial management" .)