- phenomenon
- 1570s, "fact, occurrence," from L.L. phænomenon, from Gk. phainomenon "that which appears or is seen," noun use of neut. prp. of phainesthai "to appear," passive of phainein (see phantasm). Meaning "extraordinary occurrence" first recorded 1771. Plural is phenomena. Shortened form phenom is baseball slang, first recorded 1890.