Facetious and abstemious are unusual words becxause they contain all the vowels in the correct order, as does arsenious.
Arsenious is one of those words that sounds as though it should be used after the 9 pm watershed but actually it's quite innocuous. It simply means containing arsenic.
"Realgar, derived from the Arabic rahj al ghar (meaning powder of the mine), is arsenious - it was known in ancient times and was once used as a pigment."
Toby at Six Months
13 hours ago