An Etymological Dictionary of Astronomy and Astrophysics

To think carefully about, especially in order to make a decision; contemplate; reflect on (dictionary.com).

Etymology (EN): M.E. consideren, from O.Fr. considerer “reflect on, study,” from L. considerare “to examine, look at closely,” literally “to observe the stars,” from → com- “with” + sider (stem of sidus) “star, group of stars,” → sideral.

Etymology (PE): Âgâridan, from intensive prefix â- + gâr-, variants gar-, gâl-
“to consider, observe,” as in engâridan “to suppose,”
negaristan “to observe, look, notice,”
segâl “thought,” segâlidan “to think, meditate,” ultimately from Proto-Iranian *kar- “to observe, to consider;” cf. Av. kar- “to remember; to impress on memory;” Skt. kal- “to observe, consider,” kalayati “considers, observes.”