Don't ligaments connect bone to bone? In the eye for example, the suspensory ligaments connect the ciliary muscle to the lens, which obviously aren't bones. Is this just one of those instances where the terminology isn't that precise and you just have to memorize the exception?
"...The suspensory ligaments connect the ciliary muscle to the lens..."
You must be referring to the Zonule of Zinn (Such a great name).
You are absolutely correct, the definition of Ligament varies across texts which can create confusion.
Merriam-webster: A tough fibrous band of tissue connecting the articular extremities of bones or supporting an organ in place.
Wikipedia: A ligament is the fibrous connective tissue that connects bones to other bones.