Take the adjective coy for a person who pretends to be shy but really isn't, or someone who could give a definite answer but won't. Coy behavior can be playful or just plain annoying.

Originally meaning "quiet and shy," today someone who is coy pretends to be shy in a playful manner — often as a form of flirting. If a politician is coy about something, he or she only gives vague statements on an issue for fear of committing to a position or angering his or her constituency. Common to both of these senses is the fact that a person uses coyness to subtly manipulate his or her audience.

Definitions of coy
  1. adjective
    affectedly modest or shy especially in a playful or provocative way
    synonyms: demure, overmodest
    not offensive to sexual mores in conduct or appearance
  2. adjective
    showing marked and often playful or irritating evasiveness or reluctance to make a definite or committing statement
    “a politician coy about his intentions”
    vague or not clearly defined or stated
  3. adjective
    modestly or warily rejecting approaches or overtures
    “like a wild young colt, very inquisitive but very coy and not to be easily cajoled”
    showing fear and lack of confidence
Word Family