A mondegreen of "and per se and", meaning "and (the character) '&' by itself", which is how the symbol (&) was originally referred to in English. This formulation is due to the fact that in schools, when reciting the alphabet, any letter that could also be used as a word in itself ("A," "I," "O" and, at one point, "&") was preceded by the Latin expression per se ((deprecated template usage) [etyl] Latin for "by itself"). Also, it was common practice to add at the end of the alphabet the "&" sign, pronounced "and". Thus the end of the recitation would be: "X, Y, Z and per se and." This last phrase eventually became "ampersand", and the term was in common English usage by around 1837.
Pronunciation
Lua error in Module:parameters at line 95: Parameter 1 should be a valid language or etymology language code; the value "UK" is not valid. See WT:LOL and WT:LOL/E.IPA(key): /ˈæm.pə(ɹ).sænd/, /ˈæmp.ə(ɹ)ˌzænd/