lifetime
n. countablen. the length of time that someone is alive or that something lasts. It can also mean a very long time when you are exaggerating.
n. the duration of a person's life or the period during which an object or system remains functional. Often used hyperbolically to indicate an extensive period of time.
He spent his entire lifetime living in the same small village.
Modern appliances are often designed with a shorter lifetime than those manufactured several decades ago.
The philosopher argued that a single lifetime is insufficient to grasp the complexities of human nature, requiring instead the collective wisdom of many generations.
From Middle English lyftyme, equivalent to life + time. Cognate with Icelandic líftími (“lifetime”). Compare also Saterland Frisian Lieuwendstied, Dutch leeftijd and levenstijd, German Low German Levenstied, German Lebenszeit, Danish livstid, Swedish livstid.
Often used in the phrase 'of a lifetime' to describe a unique or rare opportunity.