Tyranid Etymology

The Tyranid Threat
Since our first sporadic contacts with Genestealers there have been many misconceptions associated with them. We first thought they were indigenous to the moons of Ymgarl, later this was determined to be in err and subsequently a xenocide campaign was conducted on said moons. When the Tyranid hivefleets came upon the Imperium, the creatures were named in relation to the first notable plant to fall before their advance, the exploratory station of Tyran. – Draco Legion Biomedical Reserch station: NewHallefuss

Origin of the Species
Most of the Tyranid organisms in the Warhammer 40k universe have been given Latin or Greek names. This makes them sound more exotic and fits with the general use of Latin by the Imperium. I can not really take credit, beyond compilation, for this etymology as it is all taken from other websites, particually Wiktionary.

Biovore – This suffix comes from the Latin vorare (to devour), and is used to form nouns indicating what kind of a diet an animal has. From Ancient Greek βίος (“life”). Therefore, a biovore eats life.

Carnifex – The public executioner at Rome who put slaves and foreigners to death. It was also his business to administer torture. This office was considered so disgraceful, that he was not allowed to reside within the city.

Gargoyle – The term 'gargoyle' was derived from French gargouille meaning 'throat', which originated from the Latin gurgulio meaning 'gullet'. Gargoyles were used to decorate buildings, and to provide a spout for rainwater run-off. A decorative carved grotesque winged figure on a building. There is also a French legend about a dragon-like monster called Gargouille.

Gaunt – Meaning lean, angular and bony

Harridan – Modification of French haridelle (“old horse, nag”).

Harpy – Greek Mythology. One of several loathsome, voracious monsters with the head and trunk of a woman and the tail, wings, and talons of a bird

Hierodule – From the Greek "temple" + "female slave"), was a temple slave in the service of a specific deity, often with the connotation of religious prostitution.

Hierophant – From ancient Greece is an interpreter of sacred mysteries and arcane principles.

Hormagaunt – A legendary undying monster that steals children and lives on the supposedly mythical planet Thamber in the Killing Machine (1964) a science fiction novel by Jack Vance. The only real world reference is Hormah (meaning "devoted to destruction") in the Bible. Numbers 21:3 – And the LORD hearkened to the voice of Israel, and delivered up the Canaanites; and they utterly destroyed them and their cities: and he called the name of the place Hormah.

Lictor – Perhaps derived from the Latin verb ligare (to bind), because the lictors had to bind the hands and feet of criminals before they were punished. They were a member of a special class of Roman civil servant, with special tasks of attending and guarding magistrates. They carried axes that symbolized the power to execute. So this would probable have been a beter name for Tyrant Guard father than a chameleon assassin.

Malefactor – A criminal. From Latin male (“ill”) + facere (“to do”).

Morloc – Maw is from Indo-European *mak- ‘bag, belly’. The upper digestive tract, especially mouth and jaws, or a perilous opening. Loc from Latin locus, meaning place or location. There is also Morlocks who are a fictional species created by H. G. Wells for his 1895 novel, The Time Machine.

Mycetic Spore – From the Greek and Latin roots, -mycete means fungus and from ancient Greek spora, “seed, a sowing”). Also a thick resistant particle produced by a bacterium to survive in harsh or unfavourable conditions (in this case dropping from orbit onto a planets surface).

Norn Queen – In Norse mythology) Norns are any of the three goddesses of fate or destiny.

Narvhal – Closest I can find is the Narwhal (a small arctic whale).  Given that the Narvhal is a space-whale I suspect this is where it is from.

Parasite of Mortrex – May come from the latin word "mortis" meaning death and “rex” meaning king. If only he had Eternal Warrior he might manage to be the King of death!

Pyrovore – This suffix comes from the Latin vorare (to devour), and is used to form nouns indicating what kind of a diet an animal has. From Latin pyr “fire”. Therefore, a pyrovore eats fire.

Ravener – From medieval French raviner 'rush, seize by force', itself from ravine 'rapine', from Latin rapina 'plundering, loot', itself from rapere 'seize, plunder, abduct'. plunder; food obtained by violence.

Shrike – Any of various birds which are known for their habit of catching other birds and small animals and impaling the uneaten portions of their bodies on thorns

Tyrannid – A passerine (perching or song) bird of the suborder Tyranni.

Termagant – In Medieval Europe, Termagant was the name given to a god that the Europeans believed Muslims worshipped. Centuarys later because of its use in theatre the term came to refer to a bullying person particularly to a quarrelsome, scolding woman. In Jack Vance's 1962 book The Dragon Masters, a subspecies is the man-sized termagant.

Trygon – Any one of several species of large sting rays. Who are capable of inflicting excruciating wounds with their venomous tail spines.

Trannofex – From the Greek words τυράννος (tyrannos, meaning "tyrant") + fex (from facere, to make or do). Literally “Maker or bringer of Tyranny”. Not quite sure how this big dumb monster makes it though…

Venomthrope – Venom is a toxic secretion in animals that is actively delivered to the target organism, either to paralyse or incapacitate. from Latin venēnum, poison + Greek anthrop- man. Literally meaning a poisonous man or person.

Zoanthrope – The word zoanthropic (Origin: Greek. Animal + man) is a descriptive term for a mental disorder in which people believe themselves to be animals. Zoanthropy kind of monomania, or delusion, in which patients are convinced that they have been transformed into an animal.

Now it has become impossible to tell where the Tyranid warrior ends and its weapon symbiotes begin. I think we can be assured that the Norn Queens will continue to work tirelessly towards forms more and more perfectly adapted for killing the inhabitants of this galaxy just as they have in others before ours. Simply put, over the coming centuries we may be out-evolved to the point of extinction. – Magos Biologis Alder Garrick