Similar to "Salacious", but combining two words such as Seductive and Delicious. Taking the SE out of Seductive and the Licious out of Delicious making the work Selicious into a word meaning seductive AND delicious.
A polite way of saying what is of or like that which is septic, that is to say: "shitty". Also, in Latin a septum is a wall, so something septicious walls one off from that which is pleasant.