Inconstant/ɪnˈkɑːnstənt/ Definition 1 of 1Pro Tip 1/3Emotionally Charged Describes someone whose feelings change quickly and unpredictably. He's an inconstant friend, one day warm and the next day cold. Pro Tip 2/3Uncertainty Expresses lack of reliability, creating an air of uncertainty. Her inconstant attendance made it difficult to plan group projects. Pro Tip 3/3Negative Tone Inconstant often implies a negative judgment and may suggest weakness. The inconstant winds made sailing a challenge.