手をこまねく
1
to fold one's arms
彼はなにもしないで手をこまねいているだけだった。
He did nothing but fold his arms.
2
to stand and watch (without interfering);to stand idly by;to look on with folded arms
3
to lie in wait;to be ready and waiting
Other forms
手を拱く 【てをこまねく】