Sentence:  He early determined to marry and wive, / For better or worse / With his elderly nurse, / Which the poor little boy didn't live to contrive: / His health didn't thrive— / No longer alive, / He died an enfeebled old <WSD>dotard</WSD> at five! 
Meaning of the word marked with <WSD> tags:  An old person with impaired intellect; one in his or her dotage.