Some I picked for the similarity in meaning, some for the sound, some for both.
[name_m]Leonard[/name_m]- [name_f]Leonie[/name_f], [name_f]Leonor[/name_f], [name_f]Leonora[/name_f], [name_u]Ariel[/name_u], [name_f]Leya[/name_f], [name_f]Leandra[/name_f], [name_f]Leontine[/name_f], [name_f]Aria[/name_f].
[name_m]Cecil[/name_m]- [name_f]Cecilia[/name_f], [name_f]Celia[/name_f], [name_f]Zilke[/name_f], [name_f]Celeste[/name_f] / [name_f]Celestia[/name_f] / [name_f]Celestina[/name_f] / [name_f]Celestial[/name_f], [name_f]Cerelia[/name_f], [name_u]Ceylon[/name_u], [name_f]Cerys[/name_f].
[name_m]William[/name_m]- [name_f]Willa[/name_f], [name_u]Billie[/name_u], [name_f]Twila[/name_f], [name_u]Abilene[/name_u] (a bit of a stretch though), [name_f]Rosamond[/name_f] / [name_f]Rosamund[/name_f], [name_u]Wylie[/name_u].
[name_f]Elizabeth[/name_f]- [name_f]Elspeth[/name_f], [name_f]Elza[/name_f] (also means ‘joy’, so it could honour [name_u]Joyce[/name_u] as well.), [name_f]Elsa[/name_f], [name_f]Eliza[/name_f], [name_f]Lilibet[/name_f], [name_f]Lilibeth[/name_f], [name_f]Elke[/name_f], [name_f]Eliana[/name_f], [name_f]Eliane[/name_f], [name_f]Elodie[/name_f], Zabeth, Azile, [name_f]Bette[/name_f], [name_f]Elsie[/name_f], [name_f]Bettina[/name_f], [name_f]Lisette[/name_f], [name_f]Ilsa[/name_f], [name_f]Ilse[/name_f], [name_f]Tibby[/name_f], [name_f]Isabeau[/name_f], [name_f]Isabetta[/name_f], [name_f]Elyse[/name_f].
[name_u]Joyce[/name_u]- [name_f]Jolie[/name_f], [name_f]Gioia[/name_f], [name_f]Allegra[/name_f], [name_f]Bayo[/name_f], [name_f]Leta[/name_f] / [name_f]Letitia[/name_f] (for [name_m]Leonard[/name_m] too).