In drought conditions, it's only right to help out (4)
I believe the answer is:
arid
'in drought conditions it's only' is the definition.
I can't tell whether this definition defines the answer.
'right to help out' is the wordplay.
'right' becomes 'r' (abbreviation).
'to help' becomes 'aid' ('aid' can be a synonym of 'help').
'out' indicates putting letters inside.
'r' going inside 'aid' is 'ARID'.
Can you help me to learn more?
(Other definitions for arid that I've seen before include "Dry and barren" , "Very dry; uninteresting" , "Extremely dry" , "Very dry, having little rain" , "Dry and infertile" .)