dormant
Meaning: sleeping, temporarily inactive
Usage: Though she pretended everything was fine, her anger lay dormant throughout the dinner party and exploded in screams of rage after everyone had left.
somnolent
Meaning: sleepy, drowsy
Usage: The somnolent student kept falling asleep and waking up with a jerk.
torpid
Meaning: lethargic, dormant, lacking motion
Usage: The torpid whale floated, wallowing in the water for hours.
languid
Meaning: sluggish from fatigue or weakness
Usage: In the summer months, the great heat makes people languid and lazy.
lethargic
Meaning: in a state of sluggishness or apathy
Usage: When Jean Claude explained to his boss that he was lethargic and didn’t feel like working that day, the boss fired him.
indolent
Meaning: lazy
Usage: The indolent student delayed starting the project until the final hour.