Sunday Rest: latus rectum. Words Not To Use Today.

 Using latus rectum in its plural form will cause no problems at all (apart from no one's knowing what you're talking about): latera recta.

But anything with the word rectum in it is going to cause embarrassment and/or sniggering - and possibly some concern.

In fact, a latus rectum is nothing to do with the digestive system, but instead it's something to do with the geometry of cones. To be precise, it's a chord that passes through the focus of a conic [I am copying this definition word-for-word as I don't really understand it] and is perpendicular to the major axis.

I'd better see if I can find a picture:

I think the latus rectum is the green line.

Hmm...

...I shall have no trouble at all avoiding using this one.

Words Not To Use Today: latus rectum. This is Latin for straight side. 

The kind of rectum that's found at the lower end of the digestive system is more properly the rectum intestinum, the straight intestine.