Is that Neil Patrick Harris?
Yes, it is, he is quoting his famous phrase "suit up", in Irish
The app give you little hints for example in this question the app gave "suit"a capital letter S, so if you already knew the answer was one word and you noticed "suit" was the only word with a capital letter theres an advantage.
Looking culaith in my culaith
It looks like “culaith” is right sometimes, but “chulaith” is right in other situations. What’s the difference?
Check the lesson "lention" right before this one.