What Is A Kiss ?

Definition of a "kiss" as per different fields...

Professor of Economics :
Kiss is that thing for which the demand is always higher than the supply.

Professor Of Accountancy :
Kiss is a credit because it is profitable when returned.

Professor Of Algebra :
Kiss is infinity because two divided by nothing.

Professor Of Geometry :
Kiss is the shortest distance between two lips.

Professor Of Biology :
Kiss is the contraction of mouth due to the expansion of the heart.

Professor Of Chemistry :
Kiss is the reaction of the interaction between two hearts.

Professor Of Zoology :
Kiss is the interchange of salivary bacteria.

Professor Of Physiology :
Kiss is the juxtaposition of two orbicularisoris muscles in the state of contraction.

Professor Of Dentistry :
Kiss is infectious and antiseptic.

Professor Of Statistics :
Kiss is an event whose probability depends on the vital statistics of 36-24-36.

Professor Of Philosophy :
Kiss is the persecution for the child, ecstasy for the youth and homage for the old.

Professor Of English :
Kiss is a noun that is used as a conjunction; it is more common than proper; it is spoken in the plural and it is applicable to all.

Professor Of Architecture :
Kiss is a process which builds a solid bond between the two dynamic objects

Professor Of Comp.Science :
What is a kiss? It seems to be an undefined variable.