tri ar ddeg

Welsh

**Welsh numbers ^(edit)**
^{[a], [b], [c]} ← 12	13	14 → ^{[a], [b], [c], [d]}
Cardinal (masculine / vigesimal): tri ar ddeg Cardinal (masculine / decimal): un deg tri Cardinal (feminine / decimal): un deg tair Cardinal (feminine / vigesimal): tair ar ddeg Ordinal (masculine): trydydd ar ddeg Ordinal (feminine): trydedd ar ddeg Ordinal (vigesimal): (non-standard) triarddegfed Ordinal abbreviation: 13eg
Welsh Wikipedia article on 13

From tri (“three”) +‎ ar (“on”) +‎ deg (“ten”).

tri ar ddeg m (feminine tair ar ddeg)

(cardinal number, vigesimal) thirteen
Synonym: un deg tri
- 1588-1620, “1 Brenhinoedd 7:1”, in William Morgan, transl., edited by William Parry and John Davies, Mallwyd, Y Bibl Cyssegr-Lan, sef yr Hen Destament a’r Newydd‎; republished London, 1804:
  Eithr ei dŷ ei hun a adeiladodd Solomon mewn tair blynedd ar ddeg, ac a orffennodd ei holl dŷ.
  Solomon was building his own house thirteen years, and he finished all his house.

Welsh mutation
radical	soft	nasal	aspirate
tri ar ddeg	dri ar ddeg	nhri ar ddeg	thri ar ddeg
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.