Support was hard for current reversal (8)
I believe the answer is:
backwash
'current reversal' is the definition.
The definition and answer can be both related to natural events as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'support was hard' is the wordplay.
'support' becomes 'back' (to back is to support or endorse).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'back'+'was'+'h'='BACKWASH'
'for' is the link.
Can you help me to learn more?
(Other definitions for backwash that I've seen before include "Unpleasant after-effects" , "Wake" .)