philematology
The scientific study of kissing.
uncountable
Although philematology (the art and science of lip-locking) remains largely unstudied, researchers have proven that kissing not only decreases levels of cortisol, a chemical that creates stress, but also increases oxytocin, a chemical that heightens feelings of affection and potentially fights depression and disease.
Where it comes from
From Danish filematologi, from Ancient Greek φῐ́λημᾰ (phĭ́lēmă, “a kiss”) + ologi (equivalent to English -ology), but compare the New Latin philēmatologiā, which appears written in Greek as φιληματολογία in the title of a 1659 book.
Adapted from the Wiktionary entry philematology (CC BY-SA 4.0).