| Language | Reflex(es) | Gloss | Grammar | Sources |
|---|
| English |
| English | eighteen | 18 | nbr.card | AHD W7 LRC |
| English | octodecimo | eighteenmo: 1/18th sheet of paper | n | AHD W7 LRC |
| English | octogenarian | person in his/her eighties | n | AHD W7 LRC |
| English | Oktoberfest | autumn festival emphasizing merrymaking and beer-drinking | prop.n | AHD LRC |
| English | eight | 8 | nbr.card | AHD W7 LRC |
| English | eightfold | 8 times the number/quantity | adj | AHD LRC |
| English | eighty | 80 | nbr.card | AHD W7 LRC |
| English | octad | group/sequence of eight | n | AHD LRC |
| English | octahedron | solid with 8 plane faces | n | W7 LRC |
| English | Octans | southern circumpolar constellation | prop.n | AHD LRC |
| English | octant | position/aspect of celestial body distant from another by 45 degrees | n | AHD W7 LRC |
| English | octastyle | (re:) building having 8 columns in front | adj | AHD CDC LRC |
| English | octave | eight day period beginning with festival day | n | AHD W7 LRC |
| English | octavo | (size of) piece of paper: 1/8 of full sheet | n | AHD W7 LRC |
| English | octet | (composition for) 8 voices/instruments | n | AHD LRC |
| English | oct(o)- | eight | pfx | AHD W7 LRC |
| English | October | 10th month (in Gregorian calendar) | prop.n | AHD W7 LRC |
| English | octonary | (re:) set/group of eight | adj | AHD LRC |
| English | octothorpe | hash (#) symbol | n | AHD LRC |
| English | octuple | (re:) eightfold amount/number | adj | AHD LRC |
| English | trisoctahedron | regular solid with 24 congruent faces | n | AHD W7 LRC |
| Old English | e(a)hta, ahta, æhta | eight (8) | nbr.card | W7 ASD LRC |
| Old English | eahtatīene | eighteen (18) | nbr.card | W7 LRC |
| Old English | eahtatig | eighty (80) | nbr.card | W7 LRC |
| Old English | eahteða, eahtoða | eighth (8th) | nbr.ord | EIE LRC |
| Old English | hundeahtatig | hundred eighty (180) | nbr.card | W7 LRC |
| Middle English | eighte | eight (8) | nbr.card | W7 LRC |
| Middle English | eightetene | eighteen (18) | nbr.card | W7 LRC |
| Middle English | eighty | eighty (80) | nbr.card | W7 LRC |
| Middle English | octave | octave | n | W7 LRC |
| Middle English | Octobre | October | prop.n | W7 LRC |
| Italic |
| Latin | octogenarius | containing eighty | adj | W7 LRC |
| Latin | octogeni | eighty each | adv | W7 LRC |
| Latin | octoginta | eighty (80) | nbr.card | W7 LRC |
| Latin | octans, octantis | eighth of a circle | adj | W7 LRC |
| Latin | octava | eighth hour | n.fem | W7 LRC |
| Latin | octavus, octava, octavum | eighth (8th) | nbr.ord | W7 LRC |
| Latin | octō | eight (8) | nbr.card | W7 LRC |
| Latin | October | October, eighth month (in Roman calendar) | prop.n.masc | W7 LRC |
| Latin | octodecim | eighteen (18) | nbr.card | W7 LRC |
| Latin | octodecimus | eighteenth (18th) | nbr.ord | W7 LRC |
| Medieval Latin | octava | eighth (8th) | nbr.ord.fem | W7 LRC |
| Portuguese | oito | eight (8) | nbr.card | TLL LRC |
| Spanish | ocho | eight (8) | nbr.card | ASD LRC |
| Old French | Octobre | October | n.masc | W7 LRC |
| French | huit | eight (8) | nbr.card | ASD LRC |
| Italian | otto | eight (8) | nbr.card | ASD LRC |
| West Germanic |
| German | Oktoberfest | Oktoberfest | prop.n.neut | AHD LRC |
| Old High German | ahtō | eight (8) | nbr.card | W7 ASD LRC |
| Old High German | ahtodo | eighth (8th) | nbr.ord | EIE LRC |
| Middle High German | aht, eht | eight (8) | nbr.card | ASD LRC |
| German | acht | eight (8) | nbr.card | ASD LRC |
| German | Oktober | October | n.masc | LRC |
| Old Frisian | achta, acht(e) | eight (8) | nbr.card | ASD LRC |
| Dutch | acht | eight (8) | nbr.card | ASD LRC |
| Old Saxon | ahto | eight (8) | nbr.card | ASD LRC |
| Celtic |
| Old Irish | ocht | eight (8) | nbr.card | EIE LRC |
| Old Irish | ochtmad | eighth (8th) | nbr.ord | EIE LRC |
| Irish | ocht | eight (8) | nbr.card | LRC |
| Scots Gaelic | ochd | eight (8) | nbr.card | LRC |
| Manx | hoght | eight (8) | nbr.card | LRC |
| Welsh | wyth | eight (8) | nbr.card | EIE LRC |
| Welsh | wythfed | eighth (8th) | nbr.ord | EIE LRC |
| North Germanic |
| Old Norse | átta | eight (8) | nbr.card | LRC |
| Old Norse | ātti | eighth (8th) | nbr.ord | EIE LRC |
| Old Norse | áttrœðr | eighty years old | adj | LRC |
| Icelandic | ātta | eight (8) | nbr.card | ASD LRC |
| Danish | otte | eight (8) | nbr.card | ASD LRC |
| Swedish | åtta | eight (8) | nbr.card | ASD LRC |
| East Germanic |
| Gothic | ahtau | eight (8) | nbr.card | ASD LRC |
| Crimean Gothic | *aþe, athe | eight (8) | nbr.card | CGo LRC |
| Balto-Slavic |
| Old Prussian | asman | eighth (8th) | nbr.ord | EIE LRC |
| Lithuanian | ãšmas, aštuñtas | eighth (8th) | nbr.ord | EIE LRC |
| Lithuanian | aštuoni | eight (8) | nbr.card | EIE LRC |
| Latvian | astôtais | eighth (8th) | nbr.ord | EIE LRC |
| Latvian | astuôni | eight (8) | nbr.card | EIE LRC |
| Russian | vósem | eight (8) | nbr.card | EIE LRC |
| Russian | vosĭmój | eighth (8th) | nbr.ord | EIE LRC |
| Old Church Slavonic | osmĭ | eight (8) | nbr.card | EIE LRC |
| Old Church Slavonic | osmŭ | eighth (8th) | nbr.ord | EIE LRC |
| Paleo-Balkan |
| Albanian | tetë | eight (8) | nbr.card | EIE LRC |
| Albanian | tetë(t) | eighth (8th) | nbr.ord | EIE LRC |
| Hellenic |
| Homeric Greek | ὀγδόατος | eighth (8th) | nbr.ord | EIE LRC |
| Greek | ὄγδοος | eighth (8th) | nbr.ord | EIE LRC |
| Greek | ὀκτώ | eight (8) | nbr.card | EIE LRC |
| Armenian |
| Armenian | ut' | eight (8) | nbr.card | EIE LRC |
| Indo-Iranian |
| Avestan | ašta | eight (8) | nbr.card | EIE LRC |
| Avestan | aštəma- | eighth (8th) | nbr.ord | EIE LRC |
| Sanskrit | aṣṭamá- | eighth (8th) | nbr.ord | EIE LRC |
| Sanskrit | ashtan | eight (8) | nbr.card | ASD LRC |
| Tocharian |
| Tocharian B | okt | eight (8) | nbr.card | EIE LRC |
| Tocharian B | oktante | eighth (8th) | nbr.ord | EIE LRC |
| Tocharian A | okät | eight (8) | nbr.card | EIE LRC |
| Tocharian A | oktänt | eighth (8th) | nbr.ord | EIE LRC |