Lionel loses Lil, now single (3)
I believe the answer is:
one
'single' is the definition.
(a single thing - only one)
'lionel loses lil' is the wordplay.
'loses' indicates named letters should be taken away.
'lionel' with 'lil' taken away is 'ONE'.
'now' is the link.
(Other definitions for one that I've seen before include "Identical; number" , "I can mean this" , "Half of two" , "doesn't count for much" , "If upper-class, perhaps I" .)