Untranslatable Words?

We, translators and interpreters, have the challenging but fascinating job of expressing the same idea in different languages. There's a whole mental process involved, which in the case of interpreters requires extra effort as it should be performed fast.  

Throughout my career I've encountered words that imply the use of paraphrasing techniques in the target language due to the lack of a word with exactly the same denotation (http://www.merriam-webster.com/thesaurus/denotation) and connotation (http://www.merriam-webster.com/dictionary/connotation).

One of the words that poses difficulty to me is insightful, which means showing a very good understanding of a person or a complicated situation, Macmillan dictionary. We can collocate this adjective with  parent/book/behaviour/article/commentary. A suitable word in Spanish would be perceptivo, which means having the capacity to receive sensations through the senses. However, does this mean that you show a good understanding of a person or complicated situation. I wonder... Other adjectives in Spanish that would be used to express this idea would be revelador, intuitivo. Thus, un comentario revelador would be one that offers good understanding of a person or complicated situation. I'm not sure the whole concept is depicted in this way. 

Can you think of adjectives in Spanish that reflect the whole concept imbedded in the term insightful?

Have you had trouble finding a word in the target language that really expresses that idea conferred in the source language? Please share! I'd like to know.

My favourite Word this Week...

My favourite Word this Week... 

Complicity

I heard this word at the end of a radio programme as the presenter thanked his listeners for their complicity and I wondered what the word connotes, denotes and evokes. I looked it up in the dictionary and was surprised to find out the following:

the fact that someone is involved in or knows about something bad that happens 

(http://www.wordreference.com/definition/complicity)

So, does it mean the radio programme presenter was doing something wrong? Of course not.

I did a bit of research and read that Virginia Woolf 
( http://en.wikipedia.org/wiki/Virginia_Woolf) also used the word complicity to refer to the relationship between writers and readers. Again, does this mean the writer was involved in some kind of misbehaviour? I don't think so.

As I was not satisfied with the dictionary definition of complicity, I concentrated on the way I perceived the word. As far as I am concerned, this word implies a close relationship between people with a certain degree of secrecy and confidentiality. Profound closeness with other people we usually interact with involves the appearance of shared codes. Looking into this matter a little further, I've concluded that we hold as many instances of complicity as there are people we interact with. Thus, I propose a new concept for this word: secrecy that arises in our interaction with another person that depends on the kind of relationship one has with that person.

Do you know other words you feel the dictionary definition is unsatisfactory? Please feel free to share them.