Walk across hotel to find yarn (6)
I believe the answer is:
thread
'yarn' is the definition.
(I know that yarn can be written as thread)
'walk across hotel' is the wordplay.
'walk' becomes 'tread' (treading is a kind of walking).
'across' indicates putting letters inside.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'tread' placed around 'h' is 'THREAD'.
'to find' acts as a link.
(Other definitions for thread that I've seen before include "Fine cord for sewing" , "Thin strand" , "Strand of yarn" , "Ridge around a screw" , "Fine cord of twisted fibres" .)