a firework that moves in serpentine manner when ignited
"The crowd gasped as the serpent rocketed across the night sky, leaving a long, twisting trail of sparks behind it."
an obsolete bass cornet; resembles a snake
"The antique brass serpent, shaped like a coiled snake and once used as a bass cornet in early band concerts, now sits silent on the museum shelf."
A snake.
"The old gardener hissed when he saw a venomous serpent slither across his prize roses."
To wind or meander
"The old garden hose lay coiled like a serpent across the cracked pavement, waiting for water to be turned on."
Serpens (constellation)
"The amateur astronomer adjusted her telescope to track the faint stars of Serpens as they dipped below the horizon."