I understand that ‘loose’ was the proper term for releasing a volley before gun powder was invented but when a piece of siege equipment with a flaming projectile was used would they use the term fire? And if not what was the term used to call a stop to the barrage rather than ‘cease fire!’ Thanks!
The premise of your question is wrong: there was no "proper term for releasing a volley" with any weapon prior to the musket. As u/Hergrim has pointed out in an older thread, archers probably did not fire in volleys. The whole idea is just movie/fantasy authors projecting modern military concepts back into the past. It's not very likely that torsion artillery did so either.