Eruptors mostly love getting upset over kayaks (9)
I believe the answer is:
volcanoes
'eruptors' is the definition.
I can't tell whether this defines the answer.
'mostly love getting upset over kayaks' is the wordplay.
'mostly' means to remove the last letter.
'getting upset' shows that the letters should be reversed in order.
'over' is a charade indicator (letters next to each other).
'kayaks' becomes 'canoes' ('canoe' can be a synonym of 'kayak').
'love' with its last letter taken off is 'lov'.
'lov' backwards is 'vol'.
'vol'+'canoes'='VOLCANOES'
Can you help me to learn more?
(Other definitions for volcanoes that I've seen before include "Lava spewers" , "Fissures in the earth's surface that emit lava" , "Erupting fissures in the earth's crust" , "sources of warm flows" .)