Computer fit to be installed in Times (6)
I believe the answer is:
tablet
'computer' is the definition.
'fit to be installed in times' is the wordplay.
'fit' becomes 'able' ('able' can be similar in meaning to 'fit').
'to be installed in' means one lot of letters goes inside another.
'times' becomes 'tt' (two abbreviations for time).
'able' going within 'tt' is 'TABLET'.
(Other definitions for tablet that I've seen before include "Small computer" , "Small slab or flat pill" , "Prescription" , "Medicine - flat slab - computer" , "Weekly" .)