to be disconnected, to get out of place, to be off, to be out (e.g. of gear)
概論
[がいろん]
N2
introduction, outline, general remarks
ふた
[蓋]
N2
Cap. Cover, 《local Japanese language attached》 2. Two. 〔Reference〕 To accurately convey the number word, it is also used with the reading of 「二」, (shells, etc.) shell.