I had a thread called "hot, juicy mutton" recently - I like to dress sexy. I have legs and I like to show them. However, I know that my legs look better with tights on them. I also know to skim over/camouflage my middle.
If the term applies to women past 40 who want to look "hot" then I say "poo!" to that! If it means trying to dress like a 20-year-old out on the pull with no self-awareness in terms of flaunting what they no longer have, then I think it could be appropriate.
One rule I have is: "If you wore it the first time it was trendy, you can't wear it again." So, I don't wear 80's stuff, etc. I do think that will look silly on me. The truth is, most of it looked silly when I wore it in 1992 or whenever, but I got away with it then.
I don't try to be "trendy." Being my age means that I can't pull of something like boyfriend jeans just because I'm no longer so nympnlike and delectable that I can still look good in a sack. I have to wear things that suit my figure. That may mean I will wear leggings or skinny jeans or whatever even if they're no longer "in."
A woman looks a bit silly if she's wearing things for trends with no regard to her actual figure. This goes for all ages, but is especially harsh on older women because we can't get away with it solely on the strength of our youth.