Expressions (phrases, clauses, etc.), I-adjective (keiyoushi)
to be no match for (e.g. outclassed in authority, strength or in debt to); to be unable to act on an equal basis with
Idiomatic expression
あなたにはとても頭が上がりません。I have a great esteem for you.
Also written 頭があがらない【あたまがあがらない】