Which Joe gave his name to ‘sloppy joes’? We look at five interesting sandwiches and their lexical origins.
A fixed line used in describing a curve or surface.
- ‘In the following, the feet of perpendiculars dropped from points A, B, etc. on the parabola to the directrix will be denoted A ’, B ’, etc.’
- ‘The directrix is used in the construction, which follows, mutatis mutandis, the same course as the above construction in the case of the ellipse.’
- ‘It is the pedal curve of the parabola where the pedal-point is taken as the reflection of the focus in the directrix.’
- ‘The hyperboloid is then indented and connected to a series of hyperbolic paraboloids through their common directrices, thereby leading the ensemble toward the four load-bearing points to the ground.’
- ‘The focus and directrix of a hyperbola were considered by Pappus.’
Early 18th century: from medieval Latin, literally directress based on Latin dirigere to guide.
Are you looking for a word for a foolish person? We explore twelve interesting words to describe the dunderheads in your life.
Before you run for the hills, let’s run through a list of ‘run’ expressions that are running through our minds.
The definitions of ‘buddy’ and ‘bro’ in the OED have recently been revised. We explore their history and increase in popularity.