Adjective I was painfully shy as a teenager. She was too shy to ask for help. He gave her a shy smile. Help yourself if you want more. Don't be shy.
Word History
Etymology
Adjective
Middle English schey, going back to Old English scēoh, going back to West Germanic *skeuh(w)a- (whence also Middle High German schiehe, schiech "timid, despondent," and, with alteration or variant ablaut, Middle Dutch scu, scouw "timid"), perhaps extended form of Indo-European *(s)keu̯(H)- "perceive, watch" — more at show entry 1