Sail in yacht originally housed by Dahl briefly (5)
I believe the answer is:
royal
'sail' is the definition.
(type of sail)
'yacht originally housed by dahl briefly' is the wordplay.
'originally' says to take the initial letters.
'housed by' indicates putting letters inside.
'dahl' becomes 'Roald' (author Roald Dahl).
'briefly' means to remove the last letter.
The first letter of 'yacht' is 'y'.
'roald' with its final letter taken off is 'roal'.
'y' inserted into 'roal' is 'ROYAL'.
'in' acts as a link.
(Other definitions for royal that I've seen before include "One of Queen's family" , "Imperial" , "Befitting a monarch" , "William, say" , "With kingly status" .)