The proteans in the experimental theater troupe transformed effortlessly from clown to tragedian each night.

Scholars argued that the Protean motifs carved into the temple frieze referenced the sea-god Proteus and his legendary ability to change form.

The protean weather on the coast made packing for the trip a constant guessing game.

The laboratory technician detected a protean in the serum, indicating that the protein had been slightly modified by water, dilute acid, or enzymes but had not been altered to the extent of a metaprotein.