Tugboat on the river by that bridge? (5)
I believe the answer is:
tower
'tugboat' is the definition.
(I've seen this before)
'the river by that bridge?' is the wordplay.
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'river' becomes 'r'.
'by' says to put letters next to each other.
'that bridge?' becomes 'owe' (I can't justify this - if you can you should give a lot more credence to this answer).
'r' after 'owe' is 'ower'.
't'+'ower'='TOWER'
'on' acts as a link.
Can you help me to learn more?
(Other definitions for tower that I've seen before include "Drawer" , "tractor, perhaps" , "Rise to great height" , "famous prison" , "One to pull" .)