A noun that denotes an idea, emotion, feeling, quality, generalization, representation or other abstract or intangible concept, as opposed to a concrete item, or a physical object.
A verbal form that functions as a verbal noun. (In English, a gerund has the same spelling as a present participle, but functions differently; however, this distinction may be ambiguous or unclear and so is no longer made in some modern texts such as A Comprehensive Grammar of the English Language and The Cambridge Grammar of the English Language)
In some languages such as Dutch, Italian or Russian, a verbal form similar to a present participle, but functioning as an adverb to form adverbial phrases or continuous tense. These constructions have various names besides gerund, depending on the language, such as conjunctive participles, active participles, adverbial participles, transgressives, etc.