Irritable, fractious, peevish, snappish, waspish, petulant, pettish, huffy, fretful, querulous apply to persons or to their moods or dispositions in the sense of showing impatience or anger without due or sufficient cause.
Irritable implies extreme excitability of temperament, often associated with or arising from fatigue or physical or mental distress, that makes one exceedingly easy to annoy or difficult to please.
Fractious carries a stronger implication of willfulness or of unruliness than irritable, and although it also implies extreme excitability, it suggests even greater loss of self-control; the term is often applied to animals as well as to persons.
Peevish implies childish irritability and a tendency to give expression to petty complaints or ill-humored trivial criticisms.
Snappish implies irritability or sometimes peevishness that manifests itself in sharp, cutting questions, comments, or objections that discourage conversation or sociability.
Waspish stresses testiness rather than irritability, but it implies a readiness to sting or hurt others without warrant or without sufficient warrant.
Petulant usually suggests the sulkiness of a spoiled child as well as peevishness and capricious impatience.
Pettish implies sulky or childish ill humor (as of one who is slighted or offended).
Huffy also implies a tendency to take offense without due cause, but it suggests more of a display of injured pride than pettish.
Fretful implies irritability and restlessness that may manifest itself in complaints or in a complaining tone of voice, but often is merely suggested by a lack of ease and repose.
Querulous implies an often habitual discontent that manifests itself in whining complaints or in fretfulness of temper; it often also suggests petulance.