means A very large flightless African bird with long legs and neck, the fastest runner of any bird, known for sprinting away from danger and for its powerful kick.

from From Old French 'ostruce,' itself from Vulgar Latin 'avis struthio' — literally 'the struthio bird.' The Latin 'struthio' was borrowed from Greek 'strouthion,' a 'big sparrow,' which sounds like a joke until you realize the Greeks called sparrows 'strouthos' and slapped 'great' on it for the ostrich: the 'great sparrow.' That doubled-up name (bird-bird) survived the trip into English, where the famous head-in-the-sand cowardice is pure folklore — ostriches lower their heads to tend their nests or eat grit, not to hide.