Three connected meanings, all radiating from 'pointed tip': (1) the awn/tip of a grain, (2) the writing tip of a brush or awl, (3) figuratively, the sharp tip of intellect — hence
颖悟 (yǐngwù, sharp-witted),
聪颖 (cōngyǐng, bright-minded).
颖 is also extremely common in given names for the same reason.