Greetings Pavliina :)
Being the resident Greek around here, let me give you my own twist:
Mayeb it is a version of the Greek name "Hilas" (M) meaning "gracious". Recorded female versions of the name include Hilara,
Hilaria and Hilaro.
Yep, we had a great snowy X-mas in Greece -- but probably the amount od snow you get in
June :P