Synesthesia is when two senses combine with each other and form relationships. For example, I have the most common kind: grapheme-color synesthesia. Mine looks like this. The only one that’s supposed to be black is “1”. Otherwise, the ones in black have no color associated with them.
the first one is like what i have. spatial sequence synesthesia. it also manifests most strongly when imagining months of the year, but instead of an oval mine is kind of an arc that starts on the left and ends on the right, with a weird emphasis/broadness on april (my birth month)