I have made posts before regarding designing a language for your fictional world, so now is the time for a concrete example, in the form of my own. Yes, Maldene has a dictionary, and even an alphabet. You can download the font file for the alphabet in the Downloads section of www.maldene.com, but for the language, this article is here to give you a little taste.
First off, Maldenese is a phonetic language. everything is spelled exactly as it sounds, no exceptions. This has necessitated the creation of additional letters for the alphabet ones that correspond to such sounds as "th". Thus a "t" next to an "h" would be pronounced as separate letters, and only the character for "th" would be pronounced the way we of Earth would. Also, because of the phonetic nature of Maldenese, there is no "C" or "Q". There are a bunch of additional letters, each corresponding to a unique phonetic sound, but since everyone can't read Maldene script, the words are spelled in the closest English equivalent
Another feature of the Maldene language is one word = one meaning. There are no words with multiple meanings, no sound-alike words, nothing of that sort. But, rather than limiting things as some might think, it actually open things up as well as making for a more precise language. For instance, there are 3 words for "strength", 5 words for "death", and 5 words for "thank-you". "Bromta" refers to physical strength, "ÿorm" means "mighty strength" or "great", and "Glom refers to ultimate strength, physical or otherwise. Similarly for the words for "thank-you", the root word "Fawïr" is the normal "thank-you", while others add in different suffixes to taint the meaning towards a more humble giving of thanks, a sarcastic thanks, one with a note of uncertain hesitancy, and one that refers to a true heartfelt thanks.
Words in Maldene can also be combined, or one used as a prefix or suffix to another. For instance, "zotu" is a derogatory that comes from "Zo" for evil and "Tu" for dog, just as Turen refers to a female dog which can also be a popular derogatory. One popular location on Maldene is the Great Whirlpool, named "Tedelnosho" which literally means "really big hole in the water". Of course these are but a very small selection of the words and possibilities currently available in Maldenese, but this should give you an idea of what lies within. Interested in seeing a bit more? Buy the book, read the book, then look at the appendices at the back of the book.
Of course the question arises, why bother with this stuff at all? Flavor, my dear Human, flavor, atmosphere, and personality. The more of such details and personality a world has, the more real it seems when you read it. And it is that which can draw a reader in and never let him go. Give it a try and see if I'm right.
Until then, Lashek (that means "good luck")