Imaginings are the scenes and ideas you make up in your head, the ones that are not happening in the real world. The word is almost always plural, and it sounds a little literary, as if it belongs in a story or a careful essay, not in a text to a friend. “In her imaginings, the house was full of light” means that was the picture she built, not a fact she had checked. It is close to imagination, but imagination is the power to make pictures; imaginings are the pictures themselves — and they can be sweet, silly, or a bit frightening. Though actually, English speakers often just say thoughts, daydreams, or “what I imagined” instead.