Volcanic flow (4)
'volcanic flow' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for lava that I've seen before include "Molten rock expelled by a volcano" , "Molten volcanic material" , "Volcanic emission" , "Hot molten rock" , "Obsidian" .)
'volcanic flow' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for magma that I've seen before include "Hot molten rock" , "crust's content" , "Hot fluid rock" , "Hot material" , "hot filling in crust" .)