bide one's time 等待时机；坐等时机；按兵不动

【例句】
Just hesitate a little, still bide one's time.
只是犹豫了一下，仍然按兵不动。

Tom seems to be doing nothing, but really he's just biding his time.
Tom看起来好象无事可做，其实他在等待良机。