clever and smart

The Professional Association of Teachers has voted that bright British school children should not be label(l)ed clever, but instead should be deemed successful--because among children it's not cool to be clever.

In AmE, clever is not as often used to refer to people. You might make a clever chess move or write a clever limerick, but that would prove that you were smart. In the UK these days, smart is more often used to refer to how someone dresses, rather than their intelligence.

A related BrE term is smart casual, meaning 'dressed informally, yet neatly and stylishly'. When my mother visited me in South Africa in the mid-1990s, a hotel's notice that the dining room had a smart casual dress code nearly sent her into crisis. She kept saying, "What does that mean? Can I wear slacks? What does that mean?"

The OED has a draft entry (now a full entry) for smart casual, which goes:

Chiefly Brit. Designating or characteristic of (a style of) dress which is informal yet smart, esp. smart enough to conform to a particular dress code.

I really doubt that definition would've helped my mother. Interestingly, the first use of smart casual that they've found, from 1945, comes from the New York Times, but the term, as evidenced by my mother's confusion, hasn't enjoyed the currency in the US that it has in the UK and other areas where smart is more likely to refer to dress style. Wikipedia has business casual as an equivalent for smart casual, but it isn't quite the same. You might see smart casual on a wedding or party invitation in the UK, but I can't imagine being invited to a business casual wedding.

Some clever BrE idioms are:

• clever dick, clever clogs = someone who is cleverDads have come out on top of a new survey which asked children who they thought was the cleverest person in the world. One in four (27%) children felt that their Dad was the smartest of all, with Mum's [sic] just behind with one in five (19%) of the votes.
  However, the gloss may have been taken off the victory for Mums and Dads, with some of the other results confirming that children say the funniest things. David Beckham was perceived to be a clever clogs by one in six (17%)
  --UKparents.co.uk


• to box clever = to be shrewd, to use your wits (hence the adjective boxing clever, which may be familiar to US fans of Elvis Costello and/or Placebo) Emma is finally goaded into action and realises that she must box clever to force Nadia out of her life for good. --UK TV Guide
• [That's/It's] not big or clever = It's unappealing and stupid.Yeah, so I know it's not big or clever to like Oasis, but I always did and I guess I still do. --Paste Magazine

Trying to think of smart/clever idioms that are found in general American English, but not British, is tougher--as most have made their way over. The OED lists to be/get smart (with someone), meaning 'to be impudent' as US, and it's true that one would usually hear don't be/get clever in the UK, but the American version is understandable. Similarly the [originally AmE] term street smart(s) is generally understood in the UK. There are some US regional uses of smart and clever that go back to other regional BrE uses, but those are foreign enough to me (and one expects rather old-fashioned), that I can't pretend to be an expert on them, so I'll let the American Heritage Dictionary do the talking:

In the 17th and 18th centuries, in addition to its basic sense of “able to use the brain readily and effectively,” the word clever acquired a constellation of imprecise but generally positive senses in regional British speech: “clean-limbed and handsome,” “neat and convenient to use,” and “of an agreeable disposition.” Some of these British regional senses, brought over when America was colonized, are still found in American regional speech, as in the South, where clever can mean “good-natured, amiable” in old-fashioned speech. The speech of New England extends the meaning “good-natured” to animals in the specific sense of “easily managed, docile.” Perhaps it was the association with animals that gave rise to another meaning, “affable but not especially smart,” applicable to people when used in old-fashioned New England dialects.

Smart is a word that has diverged considerably from its original meaning of “stinging, sharp,” as in a smart blow. The standard meaning of “clever, intelligent,” probably picks up on the original semantic element of vigor or quick movement. Smart has taken on other senses as a regionalism. In New England and in the South smart can mean “accomplished, talented.” The phrase right smart can even be used as a noun meaning “a considerable number or amount”: “We have read right smart of that book” (Catherine C. Hopley).

These days, on both sides of the Atlantic, smart is used more and more for technology that can apply itself in apt ways--hence smart bomb, smart card, etc. That this is used in BrE is a testament (not that we need it) to the force of American English in the world.