You're not supposed to be a dictionary!

I either tell my students that I don't know, or even better, I  take 2 dictionaries out of the cupboard and ask 2 students to try to be the first to find the translation we need.

In case  the word is too recent to be in an old dictionary, I tell them I'll look for the answer on the Internet.

 Yes, I agree with  you, but  adolescents with whom I work sometimes don't understand that :( You simply fall in  their estimation as  a  teacher.

 Recently I had such case when one of my students asked me to translate some phrases from songs ( one of which I didn't know!!!) so I have translated the first one and concerning the second one (which I didn't know) I told him to look it up in the dictionary himself :))) than I thought that was really silly of me, but now I think how to correct this mistake... I think I'll ask him whether  he had  found out the meaning of that phrase ...

 As regards your advice to give them dictionaries - that's  really good, I'll use that  strategy in future :))))

  Thanks a lot!

Dear Gvashka,

Nobody's perfect! When I started teaching I also had the same problem. We are all people with blood and flesh. We all make mistakes, the problem is what lessons we take for ourselves after that. I often had a slip of the tongue or made instant unconscious mistakes without any reason. I also felt awful. Then I often asked my students if they would forgive me for that. I always was honest with them and never tried to be better than I was. On metting a new word I often arranged a competition: who finds this word's meaning first. It's a chance to get them used to work with dictionaries, you know! On finding out the meaning themselves they'll remember it much better than being told by you. I think if you're hardworking and enthusiastic, you've already gained two points to be respected by your students. So, relax and enjoy your teaching. Remember, one who makes no mistakes - makes nothing! :-)

Hi,

I have to agree that getting the students to look up the the word/phrase is an excellent option in this situation; they both practise an important skill for autonomy in learning and they are more likely to remember the language they have made the efforts to find the meaning for themselves. You could also set finding the meaning of the word as a homework challenge for the whole class, providing, of course that it isn't needed in that particular lesson.

I personally don't think there is any shame in not knowing the meaning of a word or expression, especially when you factor in the many varieties of English around the world - in our staff room you will hear Americans and Brits explaining meanings of words to each other! Further to this, do your students know EVERY word in their native language? I suspect not.

If you feel that you need to give your students a meaning, but consider it inappropriate to say you don't know, a diplomatic, "I will note that down and I can make time in the next lesson for us to look at it in detail." is an effective alternative. (This is also a great way to deal with any grammar points that you want to brush up on before explaining them - better to delay than have to go back and undo a incorrect explanation).