Sentence:  It would authorize the Texas Education Agency to establish county-wide day schools for the deaf in counties of 300000 or more population , require deaf children between 6 and 13 years <WSD>of</WSD> age to attend the day schools , permitting older ones to attend the residential Texas School for the Deaf here . 
Meaning of the word marked with <WSD> tags:  having attained a specific age; (`aged' is pronounced as one syllable)