Engineers put tub out in wind (6)
I believe the answer is:
breath
'wind' is the definition.
(breath is a kind of wind)
'engineers put tub out' is the wordplay.
I cannot really see how this works, but
'engineers' could be 're' (Royal Engineers) and 're' is present in the answer.
'tub' could be 'bath' (synonyms) and 'bath' is located in the leftover letters.
No letters remain.
This explanation may well be incorrect...
'in' is the link.
Can you help me to learn more?
(Other definitions for breath that I've seen before include "It is drawn all the time" , "Bertha (anag.)" , "Inhale and exhale air" , "Respiration" , "Slight movement of air" .)