Most dictionaries define it as something that is usually negative. That would suggest that there are times when they are not. But, all the examples that are given are negative.
the one you just said Another example is Boris knew it was too dangerous to come out and say it directly so he used an innuendo to imply it.
A negative connotation of "hard" could be seen as difficulty, struggle, or challenge. It may imply something that is strenuous, demanding, or arduous.
When one states that something 'does not imply' something else, one is indicating that the first 'something' does not lead to or bring about the second 'something.' For example, one may say that being religious does not imply being intolerant: here, one is stating that being religious does not (necessarily, always, often, etc.) lead to intolerance.
No, binding energy cannot be negative. Binding energy is always a positive quantity that represents the energy required to hold a system together. If the binding energy were negative, it would imply that the system is in an unstable state.
Derogatory hints are things that hint at something insulting or disrespectful. Snide comments that imply something negative about another person are derogatory hints.
The connotative meaning of "greasy" often carries negative associations, suggesting something oily, dirty, or unclean. It can also imply something unpleasant or distasteful.
"Fair" typically has a positive connotation, suggesting that something is just, honest, and equitable. It can also imply that something is reasonable or done without bias.
The connotation of shock is typically negative, signaling a strong emotional response to something unexpected or unsettling. It can imply disbelief, confusion, or distress.
If something "melts in your mouth" then it dissolves quickly, and the phrase almost always also implies that whatever it is is tasty.
Kinetic energy cannot be negative because it is a measure of an object's motion and velocity, which are always positive values. Negative kinetic energy would imply that an object is moving in the opposite direction of its velocity, which is not physically possible.
"Silent" can have a negative connotation as it may imply a lack of activity, emotion, or engagement.
No. I prefer shallow and superficial wounds to other types of wounds. In a more clinical sense, you could use either one to refer to, say, a ditch. When applied to a person, they are negative.