Measured from top of seam down (4)
I believe the answer is:
slow
'measured' is the definition.
(I've seen this in another clue)
'top of seam down' is the wordplay.
'top of' indicates taking the first letters.
'down' becomes 'low' (similar in meaning).
The first letter of 'seam' is 's'.
's'+'low'='SLOW'
'from' acts as a link.
(Other definitions for slow that I've seen before include "Sluggish" , "Unhurried" , "Owls (anag.)" , "Moving at low speed" , "Not quick to understand" .)