Meow
A Meow can have a wide range of meanings, depending on what you want to communicate. It's a highly versatile way of communication. Just a tiny change of tone can change the meaning completely, and a meow can be assertive, plaintive, friendly, bold, welcoming, attention-soliciting, demanding, or complaining - or even silent.
A very important meow is the Feeding Time Meow, a special meow used to tell the humans that it's way past feeding time and you're about to starve to death.
Howling and Yowling
These two are almost like a meow, only louder and more serious. These sounds are usually for situations where we feel threatened or really, really angry. There's a reason why these sounds are loud, because we're in a situation where we really need to state our displeasure.
Sometimes, the howls and yowls are used in discussions between two cats about who owns the turf they're currently on. The objective is to be the loudest one, since that means superior lung capacity and strength, but sometimes the clearly weakest cat don't take the hint. That's when we have to fight. Can't let invaders into our homes, since that will send out a signal that any old tomcat can just waltz into our turf any time they want. And we can't have that, can we?
Eyes
To be so into eyes as humans are, they sure don't use or read clear eye communication very well. We, however, are constantly keeping an eye on other eyes than our own. Connecting eyes is a sign of dominance and slight aggression, but not if you connect eyes and blink slowly. That's a sign of trust. I mean, we would never close our eyes while looking at an enemy, so you'd better appreciate it if we close our eyes towards you!
Chirr
A chirr is an important sound. A mother will chirr to her kittens, and they will only respond to her chirrs. A chirr is also a greeting when you meet a friend. Some cats have also found out that some humans react positive to a chirr, so it might be possible to use it as a way to attain treats. More research is needed to say anything too sure about this, however.
Chirp
This is maybe one of the sounds the humans most often misunderstand. They think it's an involuntary sound we make when we hunt. However, it's hardly involuntary. It's a bit of a practice run for our killing bite. Explaining how this works is impossible to explain in words, however. If you're a cat, you'll know. If you're not, well... You wouldn't understand anyways.
Purr
The stupid humans seem to think that a purr is a sound of pleasure, and only that. However, all cats know that this is wrong. Yes, we purr for pleasure, but a purr is, as everyone should know by now, more a way to show friendliness or to ask for some needed friendliness in return. A hurting cat might purr to try to get help by asking for some friendliness from anyone who might be around. A happy cat who is purring is usually thanking the nearby cat or human for their friendliness.
Hiss
Sometimes languages borrow small parts of other languages. We would like to be able to say that the snakes stole the hiss from us, but it's probably regrettably the other way around. A hiss is a warning. If you don't leave us alone you will regret it. If you get too close to a hissing cat, you might get an additional hiss and spit - if we don't just make you regret it with our teeth and claws right away.
Headbumps
It's a good thing humans are hugging creatures. This makes it easy for us to claim places with our scent signature by rubbing against them without them noticing. They only think we're being all snuggly and nice. In fact, most cats have claimed the whole house from the humans without them noticing anything. The large dummies still think they own the place, poor souls.
Tail
The tail is an important part of the cat language, and one of the two most important parts of the body language together with the ears. There's a lot of messages that are given through the tail, like annoyed swishing, the social rise and bend, the excited vibrate, and many other more or less subtle communication. Every time a human says that "the cat bit me with no reason at all!" it's about 99.7583% sure that the cat has indeed spoken very clearly with its ears or tail - or both.
Whiskers
Not strictly a communication device in itself, we still use our whiskers to communicate in a small way. Forward pointing whiskers is one of the ways we can say we're very interested in what's happening, and want a part of it - at least if it's edible.
Ears
The cat's ears aren't just for hearing, although our vastly superior sense of hearing certainly is an important function. They are also important communication organs. Which way the ears are pointing, as well as how high or low they are, tell volumes about the cat's mood, needs and general state of mind. Together with all the other bits of the cat language, the ears make it exceptionally clear what you want to say.
So great to see the Cat-world again :D ANd such amazing level of funny details here :D
Creator of Araea, Megacorpolis, and many others.