视若无睹 [- - wú dǔ]turn a blind eye to; take no notice [heed] of what has been seen; shut one's eyes to; be undisturbed by what one has seen; give sb. the go-by:
•¶ 他脱下帽子， 正想和她打招呼， 但她却视若无睹， 扬长而去。 He raised his hat and was about to speak to her, but she gave him the go-by and kept on walking.