Only some accessing other block (5)
I believe the answer is:
ingot
'block' is the definition.
(I know that ingot is a type of block)
'only some accessing other' is the wordplay.
'only some' says the answer is hidden in the clue.
'INGOT' is hidden within 'accessing other'.
(Other definitions for ingot that I've seen before include "Block of, eg, gold" , "Brick-shaped lump of cast metal" , "E.g. a gold bar" , "Bar of bullion, for example" , "Cast metal brick" .)