friv·ol 
(frĭvəl)
(frĭvəl)intr.v. friv·oled, friv·ol·ing, friv·ols or friv·olled or friv·ol·ling
To behave frivolously.
[Back-formation from FRIVOLOUS.]
frivol·er n.
- hypophosphorous acid
- hypophyseal
- hypophysial
- hypophysis
- hypopigmentation
- hypopituitarism
- hypopituitary
- hypoplasia
- hypoplastic
- hypoploid
- hypoploidy
- hypopnea
- hypopneic
- hyposensitive
- hyposensitivity
- hyposensitization
- hyposensitize
- hypostasis
- hypostatic
- hypostatical
- hypostatically
- hypostatization
- hypostatize
- hyposthenia
- hyposthenic