Old broken chair engulfed by current (7)
I believe the answer is:
archaic
'old' is the definition.
('archaic' can be similar in meaning to 'old')
'broken chair engulfed by current' is the wordplay.
'broken' indicates an anagram.
'engulfed by' is an insertion indicator.
'current' becomes 'ac' (alternating current).
'chair' anagrammed gives 'rchai'.
'rchai' placed within 'ac' is 'ARCHAIC'.
(Other definitions for archaic that I've seen before include "From the past" , "Very old or old-fashioned" , "No longer in general use" , "Ancient or out of date" , "A long way out of date" .)