Gerund

Gerunds are deverbal nouns which inherit the subcategorization properties of the corresponding verbs. Moreover, gerunds appear in syntactic positions typical for nouns, although their behaviour is strictly speaking verbal in nature.

Example
English verbs have a gerundive counterpart ending in the suffix -ing (cf. (ii)). These nominalizations in -ing, like verbs, can be modified by adverbials, while nouns can only be modified by adjectives (cf. (iii)):

(i)  Tom critized the book Tom sarcastically criticized the book (ii) Tom's criticizing the book Tom's sarcastically/*sarcastic criticizing the book (iii) Tom's criticism of the book Tom's *sarcastically/sarcastic criticism of the book

Gerunds are also called verbal nouns.

Link
Utrecht Lexicon of Linguistics