Doesn't oirnn also mean worried/scared? How does the listener know whether the kid saying this is brave, or has just eaten?
To say we aren't frightened, you change hunger to fear. chan eil an t-eagal oirnn
What does the t signify?
It's part of the article. Some words get an, some get am, some get "an t-". It's covered in the course notes/tips under "the masculine article" at: