'Toothbrush' fuses PIE *h-dont- (tooth/eater) + brush — the tooth root also gave us 'trident' and 'indent.'
A small brush with a long handle, used for cleaning the teeth.
A transparent compound formed in English: tooth + brush. Tooth descends from Old English tōþ, from Proto-Germanic *tanþaz, from PIE *h₁dónts (tooth) — itself the participial form of the root *h₁ed- (to eat), so a tooth is literally that which eats. The PIE form *h₁dónts is the source of Greek odous (tooth, whence orthodontics), Latin dens/dentis (tooth, whence dental, dentist, indent), Sanskrit danta, Gothic tunþus, and Old Norse tönn. Brush enters English via Old French brosse, from Vulgar Latin *bruscia, probably from Proto-Germanic *bruskaz (underbrush, bristle-
'Tooth,' 'dental,' 'dandelion,' 'trident,' and 'indent' all come from PIE *h₁dónt- (tooth). A tooth is a tooth. Dental relates to teeth. A dandelion has 'teeth of the lion' ('dent de lion') — its jagged leaves. A trident has three teeth (prongs). To indent is to 'tooth into' — to make a tooth-like notch. The bristle-brush for cleaning the body's teeth links six thousand