擅自

擅自 [shàn zì]

1. ■ do sth. without authorization; take the liberty; arbitrarily:

擅自逮捕 make unwarranted arrest;

擅自决定 make arbitrary decisions;

擅自离去 leave without notice;

擅自动用 take the liberty of using sth.;

擅自提[抬]价 arbitrary price increases; raise prices without authorization;

擅自行动 take presumptuous action on one's own; act presumptuously;

擅自作主 act arbitrarily [without authority]; take an unauthorized action;

不得擅自修改。 No unauthorized changes be made.

你不在时， 她擅自用你的打字机。 She took the liberty of using your typewriter while you were away.