Wiktionary
n. The grouping together, and collective labelling, of various separate ethnicity.
Wikipedia
Panethnicity is a political neologism used to group together related ethnic groups. The term was coined in 1992 by Yen Espiritu to refer to the group of Asian Americans.
It has since seen some use as a replacement of what used to be called race; for example, Asian Americans can be described as "a panethnicity" of various unrelated peoples of Asia, which are nevertheless perceived as a distinguishable group within the larger multiracial North American society.
More recently the term has also come to be used in contexts outside of multiculturalism in US society, as a general replacement for terms like ethnolinguistic group or racial group.
The concept is to be distinguished from " pan-nationalism", which similarly groups related ethnicities, but in the context of ethnic nationalism and usually irredentism (for example, Pan-Arabism, Pan-Turkism, Pan-Iranism, Pan-Slavism, Pan-Germanism, Pan-Celticism, Pan-Africanism).