What is this Word?

1 syllable /oi/

100

noise

noise

200

spoil

spoil 

300

voice 

voice

400

join

join

500

boil

boil

2 syllable /oi/

100

avoid

avoid

200

choices

choices

300

joining

joining

400

appoint

appoint

500

poison

poison

1 syllable /oy/

100

boy

boy

200

joy

joy

300

toy

toy

400

coy

coy

500

soy

soy

2 syllable/oy/

100

employ

employ

200

decoy

decoy

300

oyster

oyster 

400

cowboy

cowboy

500

royal

royal