infect
v.
late 14c., from Latin infectus, past participle of inficere "to spoil, stain," literally "to put in to, dip into," from in- "in" (see in-(2)) + facere "perform" (see factitious). Related: Infected; infecting.
〔李〕[in-=into进入；fect=to make使……→“to make...into the body使……进入身体”→] v. spread a disease to;affect with a disease传染；侵染