to suspect; to sense
「気取る」 has another reading with different meanings.
犬は何かを気取って急に吠えた。
The dog sensed something and suddenly barked.
敵の動きを気取ったので素早く逃げた。
Having sensed the enemy's movement, I quickly fled.
異変を気取ると彼女はすぐに行動を起こした。
When she sensed something was wrong, she immediately took action.