활개치면서 << 활개치(다) + 면서 활개치다 : swing one's arms, flap the wings, flutter V+면서 : as, while, at the same time (that), with, between, during 활개치면서 걷다 : walk while swinging one's arms 활개치다 is contraction form of 활개를 치다 활개 : one's arms, one's limbs, the wings of a bird 치다 : swing, flap