Having a boner in a situation were it is inappropriate.
My girlfriend was crying and I was uncomfortably hard.
When something is super hard, or too hard.
"That math test was beef hard"
Hard science fiction is a category of science fiction characterized by an emphasis on scientific or technical detail, or scientific accuracy, or both. Typically, this is in the form of very grounded fiction without supernatural, magical, or usually aliens with an emphasis on realistic storytelling within our current knowledge of physics.
Andy Weir's the Martian and Adrian Tchaicovsky's Children of Time are great hard science fiction novels.
A person who is unable to take a joke or has no humor at all
Hey kevin is being a hard ass when i told a joke
An obese person with an aggressive, militant personality.
The chef is quite affable in public, but in the kitchen — he’s a real hard lard.
When a female becomes sexually aroused no matter her sexual preference (English UK)
"Mum just spotted Cliff Richard on Good Morning Britain and got a massive fanny hard-on"
An egg (trans person who doesn’t realise they are trans) who has been an egg for a longer than usual amount of time. Having one’s egg crack after their 40s is a usual qualifier, though this definition is somewhat subjective.
Bob: Alice is 70 and just realised she was trans after showing those signs for as long as I remember.
Claire: The life of a hard boiled egg, am I right?