to be complete taken with someone, seeing them makes you smile. And when you hear their text message alert or their ringtone your heart flutters a little bit.
Pure, uncontrollable, excitingly overwhelming, romantic thoughts/feelings towards a certain someone; brought forth and felt through the heart. Usually the more you know about someone the easier it is to find yourself smitten over them. It's more than a liking crush but less than love. It's like dipping a toe into a pool of what it is like to fall for someone; a scary process because of the vulnerability it brings about, but after all that's why it's called falling and not rising.
Even though they had been together for many years he was still so smitten with her internal and external beauty, that notice of another was totally incomprehensible.