Praise line penned by Elizabeth (5)
I believe the answer is:
bless
'praise' is the definition.
(I've seen this before)
'line penned by elizabeth' is the wordplay.
'line' becomes 'l' (used when specifying particular lines from a poem).
'penned by' means one lot of letters goes inside another.
'elizabeth' becomes 'Bess' (nickname).
'l' placed inside 'bess' is 'BLESS'.
(Other definitions for bless that I've seen before include "Make holy" , "Sanctify" , "Wish happiness" , "Call on God to favour" , "set aside for holy purpose?" .)