Nicknames for Cillian
2 nicknames, sorted by where they actually get used.
Office-safe
Cill
formal
Playground-friendly
Killy
casual
Cillian carries 2 documented short forms — Cill and Killy — drawn from its Irish-rooted roots. The list splits into 1 office-safe pick and 1 playground-friendly option so you can match the moment.