An Etymological Dictionary of Astronomy and Astrophysics

1. (v.) To fall inward abruptly under its own → gravity.
   

2. (n.) The act of falling inward abruptly under its own gravity. → gravitational collapse; → core collapse.

Etymology (EN): From L. collapsus, p.p. of collabi “fall together,” from → com- “together” + labi “to fall, slip.”

Etymology (PE): 1) Mod.Pers. rombidan “to fall apart, to crumble,” Hamadâni, Malâyeri: rommidan, Lori remese “get destroyed,” remane “to destroy a building,” possibly
cognate with E. crumble “to break into small fragments,” from O.E. cruma, akin to D. kruim, Ger. Krume “crumb,” L. grumus “heap of earth,” root of Fr. grumeau “lump.”

2. Rombeš from present stem romb “collapse” + noun suffix -eš.