Fall In Love
I define fall in love as physical and spiritual immediate anticipation of how you will be happy been with someone based on your own law or criteria.
Fall In Love is also a process from like to strong liking to caring etc that finally leads to love.
And don’t forget that if you fall in love with someone and there is harmony between both of you,it means you’ve already engage in relationship.
Fall in love doesn’t limit on Romantic Relationship alone it can also occur in friendship and other types of relationship
Fall in love is under specialty in behavioural model(as written by me) in which the specialty in someone make you fall in love with them.