Bell-wether, bellwether and bell wether are different forms of writing the same word. The word, however written, causes problems of punctuation and of usage. (There are no such words, in current English, as
bellweather and bellwhether, nor any variations of them (see Weather - whether). The Guardian Stylebook carries the warning note: "bellwether - sheep that leads the herd; customarily misspelt, misused, or both" (AWE's emphasis). Interestingly in view of this, it prefers the unhyphenated form - unlike AWE, and the OED, but like Merriam-Webster. It is, as always, important for writers to follow the prejudice of their editors, or, in the case of students, their teachers and markers.
- Literal meaning: a bell-wether is a sheep. More precisely, a wether is a castrated male sheep; a bell-wether is such a sheep that is fitted with a bell. This is to signal its presence, both to a shepherd and to the rest of the flock. The bell-wether is the leader of the flock.
- Figurative meaning: the term bell-wether is used as a metaphor for anything that appears to lead the way.
- In the USA, a bellwether [sic] state is a state in which the percentage share of votes in elections is (nearly) always the same as the eventual result nationally, and for that reason opinion polls in such a state can be regarded as a useful predictor. In state elections, the same role is taken by bellwether counties.
- In biological, environmental and geographical studies, a bell-wether species is one that is a good indicator of the health or well-being of a given environment. Trout, for example, because of their sensitivity to levels of oxygen in the water, may be regarded as a bell-wether species for the health of rivers, and butterflies, being sensitive to pollution, are a bell-wether species for atmospheric cleanliness.
- In financial circles, a bellwether stock is a share whose price, rise and fall etc, tend to lead similar behaviour in other shares, particularly in its own sectors. (This usage appears to be more common in American English; the UK stock market appears to prefer barometer stock.) A bell-wether bond is "one of a number of bond issues intended to measure the performance of the market (cf. benchmark bonds ['Those bonds which are considered to act as key indicators of market conditions']" (Moles and Nicholas, 1997).
- Beware, in using this good word, that you do not mistake its meaning. Only use bell-wether to mean 'a leader', in the sense of 'one who goes first, expecting others to follow'. In a rather broader sense, it can be used to mean 'an indicator', 'a marker of a trend'. It does NOT mean 'a warning' (as 'a bellbuoy, a buoy moored with a bell on it, which sounds because of the action of the waves, placed as a warning over a dangerous rock, a wreck or other hazard').
- Punctuation/orthography: OED gives the preferred form as that with the hyphen - bell-wether. No authority of current English ever includes an '-a-' in the word - although in Tudor times, this was common, as for example in Shakespeare (Merry Wives of Windsor, as printed in the First Folio (1623) III v. 102).
- Pronunciation: although Merriam-Webster records equal stress on the first two syllables, the preferred RP stress in British English falls on the first syllable, with a secondary stress on the second: 'BELL-weth-er', IPA: /'bɛl wɛ ðər/.