What it means
A bleeding heart is someone seen as overly soft, compassionate, or idealistic about politics and social issues, the type who always wants to help, donate, or give people the benefit of the doubt. It’s often thrown as a put-down meaning naïve do-gooder, but plenty of folks wear it proudly as yeah, I care, so what?
Usage examples
"Dave says the council should house everyone for free, and I’m like, alright mate, calm down, you bleeding heart, we’ve still got bills to pay."
"He's a bleeding heart, he'd give his last fiver to a stranger."
"The columnist sneered at bleeding hearts who wanted to help."
"Oh here we go, another bleeding heart on the timeline acting like landlords are the real villains."
"Call me a bleeding heart if you want, I still think kids shouldn't go hungry just so the numbers look tidy."
Where it comes from
The phrase has been around in English since the 18th century, first tied to the image of a literally bleeding heart as a sign of deep feeling and pity. By the 20th century, especially in US political talk, it had turned into a jab for people seen as soft, sentimental, or too eager to help.