Emily Blunt Apologizes for Calling Waitress 'Enormous' 11 Years Ago

Emily Blunt is apologizing for insulting an anonymous waitress on TV more than a decade ago -- this after social media resurfaced a clip of her mocking the woman's weight.

The actress issued a full-throated mea culpa to People Mag -- acknowledging a clip from an appearance she made on the 'Jonathan Ross Show' in 2012 ... when she was plugging "Looper" and yukking it up with the host.

At one point, Ross jokes about Americans being "enormous" at Chili's ... citing the size of burgers they get served/eat. Emily laughs and adds her own anecdote to it -- saying a Chili's server who was waiting on her during the filming of "Looper" was, indeed, humongous.

EB recreates the convo, playing up the woman's Southern accent ... and noting that this lady actually recognized Emily. It was mostly light-hearted -- but Twitter wasn't having it. Countless users accused her of fat-shaming ... and, per usual, demanded accountability.

Of course, Emily caved ... saying, "I just need to address this head on as my jaw was on the floor watching this clip from 12-years ago. I’m appalled that I would say something so insensitive, hurtful, and unrelated to whatever story I was trying to tell on a talk show."

She adds, "I’ve always considered myself someone who wouldn’t dream of upsetting anyone so whatever possessed me to say anything like this in that moment is unrecognizable to me or anything I stand for. And yet it happened, and I said it and I’m so sorry for any hurt caused. I was absolutely old enough to know better."