ともあろうものが (tomo-arou-mono-ga): Of all people; someone of your standing
～ともあろうものが (tomo-arou-mono-ga)
Meaning
Of all people; someone of your standing
Formation and usage
status N + ともあろう者が
Notation: N = noun; V dictionary = dictionary-form verb; V stem = the stem before ます; plain clause = plain-form clause; negative stem = the form before ない. Follow the attachment shown above.
Explanation
Reproaches conduct unworthy of someone's status or expected competence; can sound harsh.
Examples
教師ともあろう者が、そんな無責任なことを言うべきではない。
Someone of your standing as a teacher should not say something so irresponsible.
医師ともあろう者が、そんな無責任なことを言うべきではない。
Someone of your standing as a doctor should not say something so irresponsible.
指導者ともあろう者が、そんな無責任なことを言うべきではない。
Someone of your standing as a leader should not say something so irresponsible.
経営者ともあろう者が、そんな無責任なことを言うべきではない。
Someone of your standing as a manager should not say something so irresponsible.
政治家ともあろう者が、そんな無責任なことを言うべきではない。
Someone of your standing as a politician should not say something so irresponsible.
How related patterns differ
たる invokes a role's qualities; たらんとする aspires to it. まじき and ともあろう者が condemn unworthy conduct. べからず prohibits, while てしかるべきだ states what is proper. These forms can be strong or old-fashioned, so register matters.