There is no dislike button on twitter (to shield blue check marks ie celebrities from criticism ), so to measure dislike for a post, you can take the ratio of comments to likes. If there are far more comments than likes, then its a very disliked post.

It’s normally used to describe a reply or quote retweet getting way more likes than the original tweet

Someone on olde CTH once said it was referring to a ‘normal’ ratio on tweets of 10+ likes/hearts for every 1 comment/reply, but if you said some really stupid or inflammatory shit you’d see that ratio plunge to 1:1 or worse indicating there was a great deal more talk than simple liking and moving on and that the tweet was probably not well received, thus “ratio’d”