Synonyms for Coy (same or very similar meaning)
WordNet sense 1 (affectedly modest or shy especially in a playful or provocative way):
demure, overmodestWordNet sense 2 (not offensive to sexual mores in conduct or appearance):
modestWordNet sense 3 (vague or not clearly defined or stated):
indefiniteWordNet sense 4 (showing fear and lack of confidence):
timidFrom the ODE community, based on WordNetadd/edit