What is the meaning of "taut " in this context?

I suddenly realize who she is. She looks different from what I expected. A far cry from the yearbook photo that was printed everywhere one long-ago summer. Gone is the too-high hair, the ruddy cheeks, the double chin. She’s thinned out since then, shed the cherubic glow of youth. Time has made her a taut and weary version of her former self