Quenya 

yondë

any fairly extensive region with well-marked natural bonds (as mountains or rivers)

yondë noun "any fairly extensive region with well-marked natural bonds (as mountains or rivers)", occurring as a suffix -yondë, -yon/-iondë, -ion in regional names. (PE17:43). Note: †yondë may also be an (archaic/poetic) past tense of the verb yor-, q.v.