The empirical principle that most systems will work best if they are kept simple rather than made complex.

A kiss on the cheek that signifies the death of the receiver, as delivered by a mob boss or one with such influence.

(idiomatic, UK) Mouth-to-mouth resuscitation.

(idiomatic) To kiss one's hand, then blow on it in a direction towards the recipient.

Betraying a confidence by disclosing private information.

(slang) A dismissal

To betray a confidence by disclosing private information, especially of a sexual nature.

(US, idiomatic, vulgar, colloquial) to flatter or perform favors excessively, especially to receive preferential treatment from a boss or other superior; to behave obsequiously.

(Canada, US, slang) An obsequious person that tries to win the favor of someone, usually their superior.

(slang) A kiss between partners who are upside-down relative to each other.