Definition from Wiktionary, the free dictionary
frequentative (not comparable)
- (grammar) Serving to express repetition of an action.
- "Crackle" is an English frequentative verb derived from "crack".
serving to express the frequent repetition of an action
- (grammar) Refers to a subclass of imperfective verbs that denote a repeated action, no longer productive in English, but found in e.g. Finnish, Latin, Russian, and Turkish.
subclass of imperfective verbs that denotes a continuously repeated action
See also 
- frequentative in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
- frequentative in The Century Dictionary, The Century Co., New York, 1911
- feminine plural form of frequentativo