Being tight, your dresses split (7)
I believe the answer is:
thrifty
'being tight' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'your dresses split' is the wordplay.
'your' becomes 'thy' ('thy' historically meant 'your').
'dresses' means one lot of letters goes inside another (dress can mean cover).
'split' becomes 'rift' (I've seen this in other clues).
'thy' going around 'rift' is 'THRIFTY'.
Can you help me to learn more?
(Other definitions for thrifty that I've seen before include "Careful and diligent in the use of resources" , "Conserving" , "Careful with money" , "Not extravagant" , "Frugal - economical" .)