Jilleen is of Gaelic origin and means 'graceful'. It's a unique variant spelling of the Irish name Jill, which itself is a diminutive form of the name Gillian or Julian. The name Jilleen is rare, making it distinctive and memorable. It has been used sparingly throughout history, adding to its uniqueness.
"The name Jilleen experienced popularity spikes between the late 1950s and early 1970s, with a total of 138 babies named Jilleen born over three decades."