Tendency to split the rent there's a string attached to (5)
I believe the answer is:
trend
'tendency' is the definition.
(I know that tendency can be written as trend)
'split the rent there's a string attached to' is the wordplay.
'split' indicates anagramming the letters (letters split up and reassembled).
'there's a string' becomes 'd' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'attached to' says to put letters next to each other.
'rent' is an anagram of 'tren'.
'tren'+'d'='TREND'
'to' is the link.
Can you help me to learn more?
(Other definitions for trend that I've seen before include "Leaning; fashion" , "Drift; vogue" , "shift" , "Style, vogue" , "General direction in which something is developing" .)