Soil shortage, lacking depth (5)
I believe the answer is:
earth
'soil' is the definition.
(synonyms)
'shortage lacking depth' is the wordplay.
'shortage' becomes 'dearth' (dearth can mean a shortage or lack).
'lacking' suggests deleting specific letters.
'depth' becomes 'd' (abbreviation in geometry).
'dearth' with 'd' removed is 'EARTH'.
(Other definitions for earth that I've seen before include "Fox's underground lair" , "Dirty hole" , "our present abode" , "Meek's inheritance" , "Terra firma" .)