To b or not to b

The Romans had a verb dubitare meaning 'to doubt, hesitate or fear'. As Gallic Latin evolved into French, the verb became douter, with the same meanings; and a verb redouter emerged, also meaning 'to fear'. While the French had long dropped the letter 'b' from the word, English word-mongers, following the example of the early seventeenth century scholar Randle Cotgrave, put it back, since it so obviously derived from Latin dubitare. Note too our term 'indubitably'.

The Romans also had a verb reducere meaning (literally) 'to lead back' or 'withdraw'. Our word 'reduce' clearly is derived from it,; and we may also be familiar with the term 'reductio ad absurdum' in logic [that is, following an argument or line of reasoning until it obviously becomes untenable]. Latin reductus means 'drawn back, or remote, out of the way'. Latin reductus became Italian ridotto, and in time, French redoute.

The two lines of descent meet in the French spelling redoute, signifying two quite different things; (a) from L reductus, meaning a guarded hide-out or place of safety to which a body of soldiers may temporarily retire; and (b) derived from L redubitare, meaning 'fear' or 'dread'.

Cotgrave's helpful respelling of 'doubt' matched our even more obviously Latinate words 'dubious' and 'indubitably', and 'redoubt' was still occasionally used in our language to mean 'fear' - particularly in the term 'redoubtable' meaning 'fearsome'.

So it wasn't very bright of whoever it was that later borrowed the French version (redoute) of the Italian ridotto, meaning 'safe hide-away', to make English 'redou[b]t', and promptly spelled* it with a gratuitous and entirely misleading 'b' in the middle.

Sometimes even in modern English we spell it without the 'b'. Please (if ever you have occasion to write the word) do that thing. You know it makes sense.

*The Shorter Oxford English Dictionary recognises 'spelt' or 'spelled' as past tense of to spell*.

* Yes, spell meaning write-out-letters-to-form-words derives from the magic spell.

To b or not to b