Lilting:
Lilting is the use of vocalizations to replace words or set atmosphere of a song. It is also used to set a rhythm for dancing or playing.

Sean Nós
the term 'sean-nos' was first used in competition in 1904 as a translation from the English 'traditional singing (in the old style)', to differentiate it from the more prevalent parlour-room vibrato style.

Some of its features are:
A bare voice (not 'sweet', with a certain 'natural fierceness').
No vibrato.
No dynamic. (loud/soft)
Occasional nasalisation.
Music takes precedent over the lyric.
Often extra meaningless syllables are introduced, e.g., "Thug (a) me".
The use of the glottal stop/dramatic pause.
It's unaccompanied.
The melody varies from one verse to the next, and from one performance to the next. This is often referred to as the 'variation principle'.
And last but not least, the singing is in the Irish language.