It may be a gum. The word comes from the King James Bible where the corresponding word in Hebrew is בדלח (ḇəd�?lah) - but this is only used twice in the bible and occurs no where else but there.
The kicker is that bible scholars have offered arguments that it referrers to many things - but no one can say definitively what it is. Since the definition is lost but the word is still in use it is an ultimately unstranslatable word.
Japanese. When one inwardly holds a belief they consider true but outwardly projects another belief because of the social disfavor for the former. Similar to a toned down version of heretic when crossed with liar. Additionally, it has the connotation of proper behavior.
Spanish. The name comes from a feline of Pampas plains in Argentina and was chosen as the name for a line of Mitsubishi SUVs. It has the common usage, however, as something like 'to masturbate lazily'.
A Finnish term with no exact parallel in English but which is best approximated by the idea of an amount of something which is just right for what is needed. A equivalent of 'not too much, nor too little' achievement.
A word from Czech. It is the wonderfully mischievous use of a cell phone to call someone only to hang up before they pick up the line. The intention, instead of being a nuisance, being to signal them without being charged for the call.
I originally spotted this one in my Compact Spanish Translation Dictionary ... coincidentally my actual dictionary lacks it.
Is it in the Spanish dictionary because of a need for me to know it, is it a common characteristic to Spanish speaking people? One day you speak too many double L's as Y's and that vein on the leg just goes nuts?