The term scantily clad is commonly defined as inadequately clothed, under dressed, or wearing something that covers too little of the body, but I've seen the term used simply to describe people who are sexy or wearing clothes that are a little less than demure. Is it either lexically or semantically correct and acceptable to use the term in those contexts??
It's not strictly correct; It's hype, which in this case is literally short for "hyperbole."
A drinking game at our house (not really) involves taking a shot whenever a network anchor says "jaw-dropping," "outrage," or "gobsmacked." None of these words actually applies, but they have been devalued by overuse.
The Smothers Brothers had a bit about Tom falling into a vat of chocolate:
Tom: I just yelled fire when I fell into the chocolate Dick: Tom why did you yell fire when you fell into the chocolate Tom: Why I yelled fire because no one would save me if I yelled CHOCOLATE!!
Sort of like that. "Scantily clad" produces hits for your pics when searched for.