First day, I stick to the thread holder (7)
I believe the answer is:
distaff
'the thread holder' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'first day i stick' is the wordplay.
'first day' becomes 'd' (1st letter of 'day').
'stick' becomes 'staff' (staff is a kind of stick).
'd'+'i'+'staff'='DISTAFF'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for distaff that I've seen before include "female stick" , "Stick holding wood, in spinning" , "(referring to the women)" , "The female side in a family tree" , "Female - rod on which wool or flax is wound before spinning" .)