THe evolution of word meanings

The word "Gay" (reference info from Dictionary.com)

1.	having or showing a merry, lively mood: gay spirits; gay music.

2.	bright or showy: gay colors; gay ornaments.

3.	given to or abounding in social or other pleasures: a gay social season.

4.	licentious; dissipated; wanton: The baron is a gay old rogue with an eye for the ladies.

5.	homosexual.

6.	of, indicating, or supporting homosexual interests or issues: a gay organization.

–noun

7.	a homosexual person, esp. a male.

Usage Note: The word gay is now standard in its use to refer to people whose orientation is to the same sex, in large part because it is the term that most gay people prefer in referring to themselves. Gay is distinguished from homosexual primarily by the emphasis it places on the cultural and social aspects of homosexuality as opposed to sexual practice. Many writers reserve gay for males, but the word is also used to refer to both sexes; when the intended meaning is not clear in the context, the phrase gay and lesbian may be used. Gay is often considered objectionable when used as a noun to refer to particular individuals, as in There were two gays on the panel; here phrasing such as Two members of the panel were gay should be used instead. But there is no objection to the use of the noun in the plural to refer collectively either to gay men or to gay men and lesbians, so long as it is clear whether men alone or both men and women are being discussed. See Usage Note at homosexual.

The above states pretty much what I was going to begin with. Finding the info. saved me the trouble.
I don't know if this is happening in other parts of the world, but I have noticed in recent years that the word has evolved among young people into something new. I remember my son using the word and giggling when he was about 8 years old. I was concerned about this and explained the meaning I was aware of from my generation, as in referring to both sexes. It wasn't until the last couple of years that I've become aware of an unofficial change.

"gay" meaning stupid or ridiculous either referring to a person, object or situation. I

t's seems it can also mean "uncool" . The feeling I get is that this reference is not particularly dereogarty. It's used in a more fun and non aggressive manner. Sort of "How gay is that!" It always seems to raise a laugh. Calling someone gay in this manner is a kind of gentle tease.
I wonder if there is an official reference yet to this new meaning? I'm sure it won't be long before it will. Here is a word that has changed meaning 3 times in 3 generations.

It seems to me that the English language in general is evolving quite quickly. More examples I hear around the young people I work with are.

"Bare" - many, large quantity.
"Is it" - acknowledging an understanding of what someone has said.
"Phat" - great, wonderful, terrific (this one is listed as slang on Dictionary.com
"Hench" - similar to Phat, but not listed.

There are others. Can't think of them at the moment. Can you?