Tooth

Werdhom word conservation score = ★★★★

English: a tooth, the tooth

Dutch: een tand, de tand

German: ein Zahn, der Zahn

Danish: en tand, tanden

Norwegian: en tann, tannen

Swedish: en tand, tanden
Icelandic: tönn, tönnin

English: tusk 

From Proto-Germanic: tanþs

English: dental (involving teeth)
French: une dent, la dent

Spanish: un diente, el diente

Portuguese: um dente, o dente

Italian: un dente, il dente
Romanian: un dinte, dintele

From Latin: dēns, dentis

English: orthodontics (teeth realignment)
Greek: δόντι (dónti)

From Ancient Greek: ὀδούς (odoús)

Irish: déad 

Welsh: dant

Cornish: dans

Breton:  dant

From Proto-Celtic: dantom
 

Polish: dziąsło (gum)
Russian десна́ (desná) (gum)
Bulgarian: дъвка (dŭvka) (gum)

From Proto-Slavic: dę̄snà  

Lithuanian: dantis

Farsi:‎ دندان (dandân)

Sanskrit: दत् (dát)

Armenian: ատամ (atam)

From Proto-Indo-European: h₃dónts (tooth)

English: comb

From Proto-Germanic: kambaz (comb)

Polish: ząb (tooth)

Russian: зуб (zub) (tooth)

Bulgarian: зъб (zŭb) (tooth)

Latvian: zobs (tooth)

From Proto-Balto-Slavic: źámbas (tooth)
From Proto-Indo-European: ǵómbʰos (tooth, row of teeth)

Note: The underlined languages have been reconstructed by comparative linguistic researchers. The word may be inaccurate, as there is no archaeological record of the language at that time.