IPA: //ˈfɛnsər//
KK: /ˈfɛnsər/
A person who participates in the sport of fencing, which involves fighting with swords.
The fencer won a gold medal at the national championship.
Fencer → It is formed from "fence" (from Old French *fencier*, meaning to defend or protect) and "-er" (meaning a person who). A fencer is a person who engages in the sport of fencing, which involves defending oneself with a sword.
Think of someone who 'defends' ('fencier') themselves with a sword — that's what a fencer does.