> Yes, I type words, not letters. So I saw 'pon' and tried to type 'upon'.
"pon" is an English word, its a (perhaps rare, now) shortened form of "upon" (through age, among other things, it is established both with and without an apostrophe.)
I've only ever seen it as 'pon, which like wav'ring or 'neath, doesn't indicate to me a new word, just a poetical elision of an unwanted syllable. At any rate, word or not-word, it's rare enough that I'd think it an error if I encountered it in a typing improvement program from 2015.
Æfter ðám wordum
wyrm yrre cwóm
After those words
the wrathful wyrm
came,
atol inwitgæst
óðre síðe
awful cruel visitor
a second time,
fýrwylmum fáh
fíonda níosian
with hostile, gleaming
flood of fire to seek
his foes
láðra manna·sydaudio
líg ýðum for·
the hated humans;
the flame came forth
in waves,
born bord wið rond·
byrne ne meahte
burned shield to
the boss;
the byrnie could not
geongum gárwigan
géoce gefremman
to the young spear-
fighter lend support
ac se maga geonga
maéges scyld
but the young man,
under his kinsman's
shield
elne geéode
þá his ágen wæs
courageously
advanced,
when his own was
glédum forgrunden.
Þá gén gúðcyning
consumed by fire.
"pon" is an English word, its a (perhaps rare, now) shortened form of "upon" (through age, among other things, it is established both with and without an apostrophe.)