Pluralising the already plural

We all know the English word incident, and we all know (more or less) what it means. I say 'more or less', because a lot of us probably imagine that it means an accident, a mishap or a misdemeanour of some kind.

Actually it just means a 'happening', something that 'befalls', and is derived from the Latin word cado meaning to fall. (There was a literal 'incident' on a slippery road up which I was walking on the way to a party at Christmas. I never reached the party, but slunk home with a couple of bruises.) But you can have good incidents too, like finding a pound coin on a path in the park, or (as we did yesterday) seeing a barn owl from the living room window.

But another word from the same root is 'incidence' - signifying the frequency with which something happens -the incidence of seeing barn owls may be perhaps ten times a year in these parts, and of finding one-pound coins a great deal less, and accidentally falling over, somewhere in between.

But every now and again on telly you hear someone use the non-term 'incidences'. Nearly always they mean the (plural) 'incidents', but because they have heard the (singular) word 'incidence', they assume it means a happening, and pluralise it as 'incidences'.

Incidentally, 'incidentally' is an adverb based on the word 'incidence' - reminding us that not only bad things befall us. "Incidentally, you may like to know that I want to share my Lottery winnings with you."

Pluralising the already plural