Mamihlapinatapai (sometimes spelled mamihlapinatapei) is a word from the Yaghan language of Tierra del Fuego, listed in The Guinness Book of World Records as the "most succinct word", and is considered one of the hardest words to translate. It refers to "a look shared by two people, each wishing that the other will offer something that they both desire but are unwilling to suggest or offer themselves."[1]
It is described in Rock, Paper, Scissors: Game Theory in Everyday Life, by Len Fisher (p76), when describing the Volunteer's dilemma.
It is also referenced in Defining the World[2] in a discussion of the difficulties facing Samuel Johnson in trying to arrive at succinct, yet accurate, definitions of words.
The word consists of the reflexive/passive prefix ma- (mam- before a vowel), the root ihlapi (pronounced [iɬapi]), which means to be at a loss as what to do next, the stative suffix -n, an achievement suffix -ata, and the dual suffix -apai, which in composition with the reflexive mam- has a reciprocal sense.
The word was featured prominently in Ridley Scott's 2011 film, "Life in a Day".