One piece by queen in drag, failing to finish lines (5)
I believe the answer is:
haiku
'lines' is the definition.
(type of three-line Japanese poem)
'one piece by queen in drag failing to finish' is the wordplay.
'one' becomes 'i' (roman numeral).
'piece by queen' becomes 'k' (abbreviation for king, chess piece next to a queen).
'in' indicates putting letters inside.
'drag' becomes 'haul' (synonyms).
'failing to finish' means to remove the last letter.
'i'+'k'='ik'
'haul' with its last letter removed is 'hau'.
'ik' placed within 'hau' is 'HAIKU'.
(Other definitions for haiku that I've seen before include "Jap 17-syllable poem" , "Jap. 17-syllable verse" , "Seventeen-syllable Japanese poem" , "Japanese three-line verse form" , "Epigrammatic verse" .)