River names

‘Afon’ is of course the common Welsh word for river whilst ‘nant’ is a stream though it can also mean valley. ‘Aber’ refers to the mouth of a river or the entry of a smaller river into a larger one.  ‘Cymer’ is confluence; the meeting of two rivers.

Afon Aman ‘Aman’ is either a personal name or comes from ‘amanw’ meaning pig/let.  The river gives its name to Ammanford/Rhydaman, Glanaman and to Brynaman
Afon Bran ‘bran’ is crow and may be a reference to the colour of the water – peaty or perhaps shaded?
Afon Cennen ‘cennen’ is leek or lichen or possibly a personal name ‘Cennen’
Afon Clydach A common river/stream name in South Wales – ‘clydach’ means sheltered, strong, swift or stony.
Afon Crai ‘crai’ may mean rough or severe.  The river gives its name to the village too.
Afon Cynrig meaning not known
Afon Gwydderig meaning not known
Afon Hepste ‘dry river’ perhaps?
Afon Hydfer ‘bold stream’
Afon Llia meaning not known
Afon Mellte lightning river – perhaps due to its rising & falling quickly, or else its jagged course.  Gives its name to the village of Ystradfellte.
Afon Nedd Fechan little Neath river.  The meaning of ‘nedd’ is not known but is probably related to the R. Nidd in N. Yorkshire
Afon Pyrddin ‘pyrddin’ is the ‘pure man’ – an allusion to St David
Afon Sawdde meaning not known
Afon Senni ‘Senni’ is either a personal name or means ‘insulting’ – referring perhaps to the sound of its flow?
Afon Tarell meaning not known
Afon Taf  Afon Tawe / River Tawe ‘taf’ is an old name with similar origins to the name ‘tawe’ ‘tawe’ is an old name possibly signifying still and deep flowing.
Afon Twrch ‘boar river’ – from supposed ‘snouting’ action of its waters or perhaps ‘burrowing’ through the land?
Afon Tywi / River Towy ‘tywi’ probably signifies still and deep flowing
Afon Wysg / River Usk Either from British word ‘isca’ meaning water (the rivers Axe, Exe and Esk have the same origin) or meaning ‘abounding in fish’.
Sychryd ‘sych’ means dry
Taf Fawr big Taf – see Afon Taf
Taf Fechan little Taf – see Afon Taf