leo = with-them. It can also mean 'slush, slime'.
'Leon' can be the Irish Gaelic version of Leo.
'Will' is not an Irish word and has no meaning in Irish.
It doesn't mean anything in Irish.
Do you mean Leo the star sign? If so, it represents a lion and Leo is the Latin for lion.
It doesn't mean anything in Irish.
Nikko doesn't mean anything in Irish.
If you mean the Irish (Gaelic) it is not in that language. Irish has neither 'k' nor 'y' in its alphabet.
Patrick Leo Henry has written: 'An Anglo-Irish dialect of North Roscommon' -- subject(s): Dialects, English language
It doesn't mean anything in Irish: it's not an Irish name. I believe it's French.
"Isabelle" doesn't mean anything in Irish, but the Irish version of the name is Sibéal (shibael).
"eme" doesn't mean anything in Irish. It doesn't look like an Irish word.
Does Ballavue mean anything in Irish? I can find no example of it as a placename. 'Vue' is not a word in Irish.