the.com/extent

means The range or degree to which something exists, applies, or has happened — the size of the thing, measured end to end.

from From Latin extentus/extendere, 'to stretch out' — ex- ('out') plus tendere ('to stretch'), the same root behind 'extend' and 'tension.' It arrived in English through French in the medieval period, originally carrying a legal sense of a valuation or seizure of land (an 'extent' was literally how far your property stretched, often assessed right before the crown took some of it). The 'how far does the damage stretch' sense was baked in from the start.