What does shleamhnaigh means in English?

"Shleamhnaigh" is the past tense of the Irish verb "sleamhnú", which means "to slip" or "to slide".

So, "shleamhnaigh" translates directly to "slipped" or "slid" in English.

It can also be used figuratively, for example, "The time slipped away" would be "Shleamhnaigh an t-am ar shiúl" in Irish.