The examples listed already on this thread are good ones.

I once asked in therapy because it's one of those words that gets tossed around.
When I was a young teenager when my father was dating my stepmom, he had told me(I'll save commentary on whether that was a good parenting choice on his part) that she believed that I was manipulating him and that no he and I could not have one on one parent/child time. That's actually an example of manipulation, fyi, as it changed how he and I related, granted it was his choice.

My therapist explained that people who are manipulative are not Direct in asking for things or in expressing themselves. His example which I cannot pull clearly from memory this morning involved a conversation about someone with an addiction and how they covertly get their way. They will spin the conversation/demand in a circle and manage to get what they want. Whether it be money or something else.