It may be taken in court and in boathouse (4)
I believe the answer is:
oath
'it may be taken in court' is the definition.
The definition suggests a singular noun which matches the answer.
'in boathouse' is the wordplay.
'in' indicates the answer is hidden within the clue.
'OATH' is hidden in the letters of 'boathouse'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for oath that I've seen before include "in court, we take it" , "darn, for example" , "exasperated comment" , "Vow, sworn word" , "Swearword, expletive" .)