Dependable sort of alloy (5)
I believe the answer is:
loyal
'dependable' is the definition.
(I've seen this before)
'sort of alloy' is the wordplay.
'sort of' indicates anagramming the letters.
'alloy' with letters rearranged gives 'LOYAL'.
(Other definitions for loyal that I've seen before include "True to one's allegiance" , "Dependable" , "Faithful to country, cause or friend" , "Faithful - reliable" , "Alloy (anag.)" .)