an 'Independently Enlightened One'; or Separately or Individually (=pacceka) Enlightened One (renderings by 'Silent' or 'Private Buddha' are not very apt).
This is a term for an Arahat (s. ariya-puggala) who has realized Nibbāna without having heard the Buddha's doctrine from others. He comprehends the 4 Noble Truths individually (pacceka), independent of any teacher, by his own effort. He has, however, not the capacity to proclaim the Teaching effectively to others, and therefore does not become a 'Teacher of Gods and Men', a Perfect or Universal Buddha (sammā-sambuddha). -
Pacceka-buddhas are described as frugal of speech, cherishing solitude. According to tradition, they do not arise while the Teaching of a Perfect Buddha is known; but for achieving their rank after many eons of effort, they have to utter an aspiration before a Perfect Buddha.
Canonical references are few; Pug. 29 (defin.); A.II.56; in M.116, names of many Pacceka-buddhas are given; in D.16 they are said to be worthy of a thūpa (dagoba); the Treasure-Store Sutta (Nidhikhandha Sutta, Khp.) mentions pacceka-bodhi; the C. Nidd. ascribes to individual Pacceka-buddhas the verses of the Rhinoceros Sutta (Khaggavisāna Sutta, Sn.) - See bodhi.
See The Pacceka-Buddha, by Ria Kloppenborg (WHEEL 305/307).
See Pacceka-Buddha in the Pali Proper Names Dictionary.