bav

1) father, dad, male parent 2) the wise, the respected, saint

from PIE *pəter- "father",
presumably from baby-speak sound "pa",

pa(pa) -> ba(ba) -> pater -> vater -> fader -> father

PIE "p-" becomes Germanic "f-." Spelling with -th- reflects widespread phonetic shift in Middle English that turned -der to -ther in many words.

Sanskrit pitar-,
Avestan patar,
Greek pater,
Latin pater,
Old Persian pita,
Old Irish athir "father"

Cognate with
Latvian tetis "father",
Welsh tad,
Irish daid,
Lithuanian tėtė,
Sanskrit tatah,
Czech tata,
Latin tata "father"
Greek tata.