/di rek"triks, duy-/ , n. , pl. directrixes, directrices /di rek"tri seez', duy-, duy'rek truy"seez/ .
1. Geom. a fixed line used in the description of a curve or surface. See diag. under parabola .
2. Archaic. a directress.
[ 1615-25; ]
Usage . See -trix .