The development of the modern word "woman" is interesting. It descends from the word combination "wif" + "man". The "i" gradually changed to an "o". However the plural (women) retains the original "i" sound. The word "wif" on its own changed to our modern word "wife"[2].
A lot of our modern words which contain "-man" or "man-" in them developed in Old English. The word "mankind" for instance is present in Beowulf. It is spelled "manna cynnes" or "mancynn".
One last note, the word "wer" predates the English language. It dates back to Proto-Indo-European, and shows up in many different languages. For example in Latin it is "vir"
If you want a Beowulf side-by-side translation: https://heorot.dk/beowulf-rede-text.html
[1] Cool to see the word "sprecan" and it's similarity to modern German "sprechen".
[2] Which has always made me wonder about the phrase "I pronounce you man and wife". What meanings of "man" and "wife" were common when that phrase originated.