Sunday Rest: septicidal.

Some words spring traps for the honestly ignorant (which is, let's face it, all of us who are honest). There's autarky, for instance, which is nothing, despite the sound of it, to do with the rule of auts.

Septicidal is a particularly mean example of this sort of a word because not only is the -icidal bit is really nothing to do with killing, but the sept- bit is nothing to do with either decay (as in septicaemia) or the number seven (as in September),* either.

Septicidal is also a word where consulting the dictionary definition is almost certain to involve another search to discover what on earth it's going on about. Here's the Collins definition:

adj Botany (of a dehiscence) characterised by splitting along the sides of the seed capsule.

...and then, to make things even worse, you discover that dehiscence isn't in the dictionary. 

Anyway, this is septicidal dehiscence:


By H. Zell - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10996361. 

That picture is of the plant Ledum palustre, or wild rosemary (though it's really a rhododendron).

Anyway, as it happens the septi- bit in septicidal comes from septum, which is a dividing partition in a living thing. The -cidal bit does come from the idea of killing, though nothing at all hurt, let alone killed.

Ah well. Accusing botanists of being over-dramatic is a novelty, at least.

Word Not To Use Today: septicidal. The -cidal bit comes from the Latin caedere to kill. Septum comes from saeptum, a wall, from saepīre, to enclose.

*Okay, September isn't a great example, is it? Errr...septet, perhaps (which is like a quartet, but nearly twice the size).