the seven previous Buddhas
Abbreviation of 過去七仏 (kako shichibutsu). Refers to the seven Buddhas of the past in Buddhist tradition, including Shakyamuni and his six predecessors.
See also: 過去七仏
The Seven Buddhas refer to the seven Buddhas in Buddhism: Shakyamuni and the six Buddhas said to have appeared before him.
the seven past Buddhas
From 七 (shichi, 'seven') + 仏 (butsu, 'Buddha'). The reading しちぶつ is a standard Sino-Japanese compound reading.