dau ar bymtheg

Welsh

**Welsh numbers ^(edit)**
^{[a], [b]} ← 16	17	18 → ^{[a], [b], [c], [d]}
Cardinal (masculine / vigesimal): dau ar bymtheg Cardinal (feminine / vigesimal): dwy ar bymtheg Cardinal (decimal): un deg saith Ordinal (masculine / vigesimal): ddeufed ar bymtheg, deufed ar bymtheg Ordinal (feminine / vigesimal): ddwyfed ar bymtheg, dwyfed ar bymtheg Ordinal: ail ar bymtheg, eilfed ar bymtheg Ordinal abbreviation: 17eg
Welsh Wikipedia article on 17

From dau (“two”) +‎ ar (“on”) +‎ pymtheg (“fifteen”).

(North Wales, standard, colloquial) IPA^(key): /ˌdaɨ̯ ar ˈbəmθɛɡ/
- (North Wales, colloquial) IPA^(key): /ˌdaɨ̯ ar ˈbəmθaɡ/
(South Wales) IPA^(key): /ˌdai̯ ar ˈbəmθɛɡ/

dau ar bymtheg m (feminine dwy ar bymtheg)

(cardinal number, vigesimal) seventeen
Synonym: un deg saith
- 1853, Y dysgedydd, page 384:
  Y mae yn dda genym weled cynnifer a dauarbymtheg o feirdd wedi cymeryd y maes yn erbyn yr arferiad gwrthun o gysgu mewn addoliad.
  We are glad to see as many as seventeen poets have taken the field against the monstrous practice of sleeping in worship.

The vigesimal dau ar bymtheg can only be used with masculine nouns whereas the synonymous decimal un deg saith can be used with nouns of any gender.

Welsh mutation
radical	soft	nasal	aspirate
dau ar bymtheg	ddau ar bymtheg	nau ar bymtheg	unchanged
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.