プログレッシブ和英中辞典(第4版)の解説
てのうち【手の内】
❶〔腕前〕
手の内を見せる
display one's skill
❷〔心の中の考え〕one's intentions
手の内を読まれた
He saw through my intentions.
絶対に手の内を見せなかった
He never laid his cards on the table./He never revealed his hand.
❸〔勢力の及ぶ範囲〕
手の内に丸め込む
lead a person by the nose/wind a person around one's little finger
彼らはボスの手の内にあった
They were under their boss's thumb.