Is tryptophan an aromatic amino acid?

Yes, tryptophan is an aromatic amino acid.

An aromatic amino acid is an amino acid that contains an aromatic ring.

The structure of tryptophan is

The sidechain is an indole group.

It consists of a benzene ring fused to a pyrrole ring.

The ##"N"## atom is ##"sp"^2## hybridized, so its two lone pair electrons plus the 8 electrons from the ##"C"## atoms make an aromatic 10 π system.

That makes tryptophan an aromatic amino acid.