EC in time to disintegrate (5)
I believe the answer is:
decay
'disintegrate' is the definition.
(I know that disintegrate can be written as decay)
'ec in time' is the wordplay.
'in' indicates putting letters inside.
'time' becomes 'day' (day is a kind of time).
'ec' inserted within 'day' is 'DECAY'.
'to' is the link.
(Other definitions for decay that I've seen before include "Decompose or fall into ruin" , "Rot, perish" , "Decline, decompose" , "Rot, moulder" , "Atrophy" .)