(graph theory) A graph which can be embedded in a plane in such a way that its edges only intersect at vertices, i.e., they do not cross each other.

plural of planetary nebula nucleus

(astronomy) The remnant hot luminous core of the stellar progenitor of the planetary nebula, which ionizes the surrounding planetary nebula.

(New Zealand, obsolete) The tutu, a shrub of New Zealand.

scorpionweed (genus Phacelia)

(optics) achromatic throughout a plane

(transitive, slang) To pay (an amount of money).

(transitive, slang) To pay (an amount of money).

(geometry) A three-dimensional vector space over the field of real numbers in which one-dimensional linear subspaces are considered as “points” and two-dimensional linear subspaces are considered as “lines”. Equivalently, a sphere in which pairs of antipodal points are considered as “points” and great circles are considered as “lines”.

The plant Saxifraga stolonifera.