Some choices: sleepy, wasted, torpid
beat, worn, lame (as in a "lame excuse")
Lethargic, indolent
Lethargic is a word that means tired, lazy sluggish, so antonyms of lethargic would be energetic and active.
tired
Consumed is a synonym for tired. It begins with the letter c.
lifeless, sluggish
strayd
Sluggish or lagging would do
It is derived from the word 'Cansada' which means 'tired' in Spanish. It basically means 'a bit tired' or 'a little tired.'
tired
spent
tired
There are no perfect rhymes for the word sluggish.