noun which may take the genitive case particle 'no', noun
highest ever; record-high; most on record
Used in news and formal contexts to describe a number or amount that is the highest since records began. Often modifies a following noun with の.
今年の夏の気温は過去最多を更新した。
This summer's temperatures hit a record high.
過去最多の応募があった。
There were a record number of applications.
Compound of 過去 (past) and 最多 (most numerous). A straightforward modern coinage used in statistics and reporting.