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

1) To continue steadfastly or firmly in some state, purpose, course of action, or the like, especially in spite of opposition, remonstrance, etc.
2) To last or endure tenaciously (Dictionary.com).

M.Fr. persister, from L. persistere "abide, continue steadfastly," from → per- "thoroughly" + sistere "come to stand, cause to stand still," → resist.

Paristâdan from par-, → per-, + istâdan "to stand," → resist.

The act or fact of persisting; the quality of being persistent.

Verbal noun from → persist.

Persisting, especially in spite of opposition, obstacles, discouragement, etc.; persevering (Dictionary.com).

Adjective from → persist.

An → X-ray source that does not display emission → outbursts, in contrast to → X-ray transients.

→ X-ray; → persistent.