Two dictionary definitions are "Excessively meticulous; fussy" and "exacting especially about details; "a finicky eater"; "fussy about clothes"; "very particular about how her food was prepared"" There are many synonyms at: http://www.thefreedictionary.com/picky It basically means someone who is hard to please, because they are very concerned with every single detail of something. They are too picky about their food if the food is not served/made/cooked *exactly* (to the least detail) as they want.

"Picky" is for a person who is very particular about what they want, often unnecessarily so to the rest of us who aren't so "picky." Usually when I hear the word "picky," I hear it used in reference to eating habits. "My sister is such a picky eater. On the other hand, I'll eat anything." Speaker A: Have you picked a college yet? Speaker B: No, I haven't. I'm being VERY picky about where I go. Speaker A: Well, you better decide soon!

It means "particular" or "hard to please". It's OK to be picky, just not too picky. Say "I'm too picky about which college I want to attend".