Letting the Idioms out of the bag

Let the cat out of the bag / Not my cup of tea / Spill the beans / Clear as mud.

The Story

Idioms have been on my mind lately.  For example, I'd been wondering how actually to define an idiom, and what idioms students really need to know.  I also had vague recollections of looking through an Academic English textbook a couple of years ago that insisted students be taught that words such as 'affluent' are idioms, because of the Latin etymology from ad+fluere = flowing towards.  While this may be linguistically accurate, it's hard for me to imagine any student being enough of a language nerd to be helped by such an approach.  Anyway, isn't all speech necessarily figurative, when we decide that a sequence of sounds represents meaning?

Reteach, reuse, recycle - activities to help vocabulary to stick.

Confession time: reviewing vocabulary with students is not my strongest point. This isn't necessarily a problem, since many higher level classes don't need so much help: I've tended to advise students on how they can research a word online to learn pronunciation, definitions, collocations, related words and example sentences then largely leave them to it. (1)

But there are students who don't yet have these independent study skills, and generally also for lower levels much more scaffolding will be needed.

So here's a roundup of ideas and activities for reviewing vocabulary from around the web, and a few thoughts of my own.