flatus：肠胃胀气，屁，阵风，气息，一阵风   

词根词缀： -flat-吹 + -us名词词尾

• outline
• outlook
• outmanoeuvre
• outmoded
• outnumber
• outpace
• outpatient
• outperform
• outplacement
• outplay
• outpoint
• outpost
• output
• outrage
• outrageous
• outreach
• outrider
• outrigger
• outright
• outset
• outside
• outsider
• outskirts
• outsmart
• outsource