Herbaceous rhymes with:
sebaceous, audacious, capacious, ceraceous, crustaceous, efficacious, fallacious, flirtatious, gracious, hellacious, horatius, ignatius, loquacious, mendacious, ostentatious, perspicacious, predaceous, proteinaceous, salacious, sebaceous, spacious, tenacious, vexatious, vivacious, voracious
Herbaceous sounds like:
harbach, harbaugh, harbeck, harbuck, harps, harvey's, herb's, herbeck, herbig, herbs, herpes, hirabayashi, horrific, horvac, horvac's, hrabak, hrubik