Soil regularly gets into mangle and grinder (5)
I believe the answer is:
molar
'grinder' is the definition.
(I know that grinder can be written as molar)
'soil regularly gets into mangle' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'gets into' indicates putting letters inside.
'mangle' becomes 'mar' (I've seen this in another clue).
The alternate letters of 'soil' are 'ol'.
'ol' going inside 'mar' is 'MOLAR'.
'and' is the link.
(Other definitions for molar that I've seen before include "that could be capped" , "Chewer and grinder" , "Large tooth" , "Moral (anag.)" , "Grinding tooth in the back of a mammal's mouth" .)