Does the term "sustained" mean a period of time that is sustained?

As defendant correctly notes, several years before his trial was conducted one appellate court did define "sustained." It wrote: "[W]e find that it means a period of time that extends beyond what is momentary, fleeting, or transitory." (People v. Allen (1995) 33 Cal.App.4th 1149, 1156.) This definition⁵ was rendered in the context of evaluating a contention that the evidence was insufficient to sustain a conviction for making a terrorist threat, not in the context of determining the scope of a trial court's duty to instruct on the elements of the offense. Nonetheless, the case is helpful because it furnishes a definition for "sustain" that assists in determining if the error was prejudicial.