The Welsh Word for Blue: Glas

The Welsh word for “blue” is glas or las in its mutated form following feminine nouns. 

  • yr aderyn glas (the blue bird)
  • y faner las (the blue flag)

Dark blue is glas tywyll or dulas, whereas light blue is glas golau or goleulas.

What’s interesting about the word glas is that it once covered a wider range of colours than just “blue” as it is interpreted in modern English.

For example, it could be used to refer to shades of “green” if you were talking about leaves, grass, fields, pastures, vegetables, immature fruit or foliage, or “grey/silver” for coins and metal. 

These days, its use for anything other than “blue” is far more restricted due to the heavy influence of English but you’ll still see it in historic words and place names such as: 

  • gwelltglas = grass (literally “green hay”)
  • Mae’r ddaear yn glasu. = The earth is greening.
  • Ynyslas = Green Island
  • Maesglas = Green Field
  • swllt glas = silver shilling

Can you think of any interesting words containing glas? Let us know in the comment section below!


About The Author

Heather is passionate about everything language-related. Born and raised in Toronto, Canada, she holds a TEFL certification from Aberystwyth University and a Bachelor's degree in Linguistics from the University of Western Ontario. Along with her native English, she speaks Italian, Welsh, and a smattering of Japanese and French.