ichidan verb, transitive verb
be at a loss after much thought; rack one's brains in vain; think and think but get nowhere
Describes the state of having thought hard about something but being unable to reach a conclusion or find a solution. Often implies frustration or mental exhaustion.
何度も考えあぐねた末、結局あきらめた。
After racking my brains over and over, I finally gave up.
彼はその問題について
He is at a loss over that problem.