Word terfs with one letter changed

Letter on position 1 (t) changed: 2 words

kerfs
serfs

Letter on position 2 (e) changed: 1 word

turfs

Letter on position 3 (r) changed: 1 word

teffs

Letter on position 4 (f) changed: 5 words

Letter on position 5 (s) changed: 1 word

terfe