1. peen - Noun
2. peen - Verb
A round-edged, or hemispherical, end to the head of a hammer or sledge, used to stretch or bend metal by indentation.
The sharp-edged end of the head of a mason's hammer.
To draw, bend, or straighten, as metal, by blows with the peen of a hammer or sledge.
Source: Webster's dictionaryThat way you can flatter your midsection and your giant fake peen. Source: Internet
If the “pen” pronunciation is gaining on the “peen,” it may be, as you suggest, because of the “peen” resemblance to “penis” and “penile.” Source: Internet
You can BJ away as usual by placing a hand around the base of his peen and leaving it there throughout, working just the top exposed portion with your mouth. Source: Internet