The (polite) Four Letter Word Game

duke

ukes

:guitar: :guitar:

http://www.oxforddictionaries.com/definition/english/uke

auks

:bird: :bird:

upas

:evergreen_tree:

http://www.oxforddictionaries.com/definition/english/upas

paua

:shell:

prau

:rowboat:

http://www.oxforddictionaries.com/definition/english/proa?q=prau

pula

pule

:crying_cat_face:

http://www.oxforddictionaries.com/definition/english/pule

pulk

sulk

slue

:ship:

http://www.finedictionary.com/slue.html

lues

:thermometer_face:

http://www.oxforddictionaries.com/definition/english/lues

sull

http://www.finedictionary.com/Sull.html

lugs

legs

sell

bell

:bell:

dell

lade

http://www.finedictionary.com/lade.html

odea

http://www.oxforddictionaries.com/definition/english/odeum?q=odea