Could you sail it with a companion in going up the Tay? (5)
I believe the answer is:
yacht
'could you sail it' is the definition.
I can't judge whether this definition defines the answer.
'a companion in going up the tay?' is the wordplay.
'a companion' becomes 'ch' (Companion of Honour).
'in' means one lot of letters goes inside another.
'going up' says the letters should be written in reverse.
'tay' in reverse letter order is 'yat'.
'ch' put into 'yat' is 'YACHT'.
'with' is the link.
Can you help me to learn more?
(Other definitions for yacht that I've seen before include "Cathy (anag.)" , "Sailing or motor vessel for cruising or racing" , "Sailboat" , "Small pleasure boat" , "Sailing-boat" .)