Makeup artist Barry M Robinson put together a wonderful PDF of industry definitions that are commonly confused or misused. "Glossary for Photographers, Models, Makeup Artists, and Stylists"
Paula's Choice "Cosmetic Ingredient Dictionary". The "Cosmetics Cop" explains not only what the ingredients are and what they do, but evaluates them for safety.
Glamazon Diaries presents their "Lesson in Designer Name Pronunciation". This is very handy. Though there is debate on a couple of the pronunciations, it is a good starting-point. I better not hear anyone I know mispronouncing haute couture after this.
"It's 'La-kwah' sweetie"
Don't worry, stylists and designers I didn't forget about you. Bizchickblogs has two glossaries that are right up your alley. "A Complete Guide to Styles, Cuts, & Fit" and "A complete guide to Fabrics".
For anyone working in film, IMDB has posted their extensive "Movie Terminology Glossary".