Phonetic:
* 吉利安 (Jīlì'ān): This is the most common and literal phonetic translation, using the closest sounding characters.
* 吉莉安 (Jīlì'ān): This is another phonetic option, slightly more common than the previous one.
Meaning:
* 吉 (Jí) meaning "lucky, auspicious": This could be combined with another character like **丽 (Lì) meaning "beautiful" for a name like 吉丽 (Jílì).
* 嘉 (Jiā) meaning "excellent, fine": This could be combined with **兰 (Lán) meaning "orchid" for a name like 嘉兰 (Jiālán).
Ultimately, the best Chinese spelling for "Jillian" depends on your preference and the specific meaning you want to convey. It's best to discuss with a Chinese speaker or name expert to get the best option for your situation.