Oh dear. I think I may be about to unleash worry, suspicion and possibly a bit of fear upon The Word Den's dear and cherished readers.
An assassin is a murderer, usually one that's been paid/inspired/instructed to do the job by someone else. I do hope you haven't got one of those about the place.
There are other assassins about, though, who do their dirty work with their tongues rather than with knives or bombs or guns. A dealer in character-assassination is to be found in every newspaper, and nearly every factory, office, church, and school.
They don't do much harm as long as everyone knows who they are.
Then there are assassin bugs. These aren't devices used by newspapers to gain access to celebrity secrets, but things like these:
Assassin bugs are sweet little creatures who inject lethal saliva into their prey - sometimes animals larger than they are themselves - causing the animals' insides to turn to liquid. The assassin bug then sucks this liquid out.
The assassin fly hunts in the same way, but it has five eyes and a very dense moustache.
Suddenly all those acid-tongued character-assassins seem almost loveable.
Spot the frippet: assassin. This word comes from the Latin word assassīnus, from the Arabic Ḥashshāshīn, those who eat hashish.
The first assassins were members of a secret sect operating in Persia and Syria from the 1000s to the 1200s who murdered inconvenient people, usually Crusaders. The name Ḥashshāshīn was originally a contemporary insult which was more to do with the Assassins being a low-class rabble than actually taking drugs.