An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) Behind in place or position; following behind.
2) Later in time than; in succession to; at the close of (Dictionary.com).

M.E., from O.E. æfter "after, next, following in time," from O.E. of "off," cf. apo- + -ter a comparative suffix.

Pas "after," → back-; pasân with place/time suffix -ân.

1) A broad glowing arc of radiance, sometimes seen high in the western sky at → twilight, caused by the → scattering effect of → fine dust particles suspended in the → upper atmosphere.
2) Lingering → radiation that remains after a violent → event such as a → gamma-ray burst. The afterglow of any gamma-ray burst is caused by an event different from the original explosion, likely by → shock waves colliding with the ambient medium. Afterglows occur in a large range of → electromagnetic  → wavelengths.

→ after; → glow.

The part of day from → noon to → evening.

→ after; → noon.

At a later or subsequent time; subsequently.

→ after; → -ward.