Many countries like backing Artificial Intelligence (4)
I believe the answer is:
asia
'many countries' is the definition.
(Asia contains many countries)
'like backing artificial intelligence' is the wordplay.
'like' becomes 'as'.
'backing' is a reversal indicator.
'artificial intelligence' becomes 'AI' (synonyms).
'ai' back-to-front is 'ia'.
'as'+'ia'='ASIA'
(Other definitions for asia that I've seen before include "Put out" , "One-third of all land" , "Stretch of land" , "Largest land-mass" , "Huge landmass" .)