"Periapsis" or "Periastron"?
No. These words are English, not Greek.  &quot;Periapsis&quot; means the point on the orbit when the two bodies are at their closest.  It doesn't matter if this good Greek or bad Greek, it is correct English.
Apsis actually derives from &quot;arch&quot; and indicates the two points where the orbital curve is most &quot;arched&quot;: ie the points of greatest curvature.  There is the &quot;periapsis&quot;: The close point of greatest curvature and the &quot;apoapsis&quot; &quot;the distant point of great curvature&quot;.
There is no such thing as a &quot;misconstruction&quot;.  The idea that a word does not mean what it means is obviously nonsensical