A seabird seen in advertisement for a lift (11)
I believe the answer is:
paternoster
'a lift' is the definition.
(paternoster is a kind of lift)
'a seabird seen in advertisement' is the wordplay.
'seabird' becomes 'tern' (I've seen this before).
'seen in' means one lot of letters goes inside another.
'advertisement' becomes 'poster' (I've seen this before).
'a'+'tern'='atern'
'atern' inserted within 'poster' is 'PATERNOSTER'.
'for' acts as a link.
(Other definitions for paternoster that I've seen before include "a continuous lift" , "supplication" , "The Lord''s Prayer" , "that could take people to a different level" , "One can get uplifted by this" .)