These are my words:
Easy
Easy, hard, lie, dice, ass
Medium
Grinding, diabolical, lutheran, devil, angel
Hard
Transcendence, ephemeral, autodidactic, omnipotent, somnambulist
Cool,
I tried to think of themes for mine:
Easy - zoo
Lizard
Monkey
Giraffe
Leopard
Elephant
Medium - school
protractor
calculator
headteacher
athletics
gymnasium
Hard - Science Museum
microbiology
climatology
electrochemistry
entomology
lepidoptery