Term: rod: any rod-shaped bacterium
Broader: bacteria: (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants | Unrelated: whistle: acoustic device that forces air or steam against an edge or into a cavity and so produces a loud shrill sound
Broader: bacteria: (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants | Unrelated: herbalist: a therapist who heals by the use of herbs