hoi

Mane (Îngilîzî)

1. (Netherlands, informal) A greeting acknowledging someone’s arrival or presence, comparable to English hey, hi
2. (Netherlands, informal) A farewell acknowledging someone's departure, comparable to English goodbye, bye
3. (dated) An exclamation of joy.

Têgeh

selam

Hevwate

hallo

👋

dag

gegroet

goedendag

👋

hey

later

tot ziens

hé

👋

doeg

👋

ciao

salu

tot later

ik zie je

salut

slukes

👋

goede dag

doei

👋

ey

Werger

oi

👋

salut

👋

ciao

hola

👋

hallo

👋

hola

👋

salve

olá

👋

γεια

hello

👋

ave

merhaba

👋

hi

👋

bonjour

👋

Wekî (IPA) tê bilêvkirin

/ɦɔi̯/

Etîmolojî (Îngilîzî)

Ji îngilîzî hatiye wergirtin: ahoy

Ji Middle English hatiye wergirtin: hoy

In summary

Possibly a spontaneous alteration of the interjection ho. The use as a joyful exclamation is attested from the 16th century; use as an informal greeting appears only in the 20th century.
Another possibility is the borrowing from English ahoy or Middle English hoy; See also ahoi.