Wiktionary
semimajor
a. 1 (context geometry English) Of or pertaining to the semimajor axis, the long axis of an ellipse 2 Less than major, but still significant
WordNet
Usage examples of "semimajor".
Drag not only reduced eccentricity by a large factor, it shortened the semimajor axis.
So I gave myself a half increase in grade, call it semimajor semiretired.
Kuiper Belt have fairly circular orbits with semimajor axes from 35 to 56 AU, and form a region that looks like a doughnut.
But the semimajor axes~ of their orbits were so tremendous-theoretically, planets could have formed as much as a light-year from this star-that even a small percentage of error in the data makes my result uncertain by Astronomical Units.