Open English Wordnet
Nouns
Adjectives
(s)questioning, quizzicalperplexed (as if being expected to know something that you do not know)“he had a quizzical expression”
(s)doubting, questioning, skeptical, scepticalmarked by or given to doubt“a skeptical attitude”, “a skeptical listener”
(s)inquisitive, speculative, questioning, wonderingshowing curiosity“if someone saw a man climbing a light post they might get inquisitive”, “raised a speculative eyebrow”