gerund

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun In Latin, a noun derived from a verb and having all case forms except the nominative.
• noun In other languages, a verbal noun analogous to the Latin gerund, such as the English form ending in -ing when used as a noun, as in singing in We admired the choir's singing.

from The Century Dictionary.

• noun The name given originally by grammarians to a Latin verbal noun, used in oblique cases with an infinitival value: as, amandi, amando, amandum, ‘loving’; hence applied also in other languages to somewhat kindred formations: e. g., in Sanskrit to forms in tvā, ya, etc., having the value of indeclinable adjectives: as, gatvā, -gatya, ‘going’; in Anglo-Saxon to a dative infinitive after tō: as, gōd tō etanne, ‘good to eat’ (that is, ‘good for eating’). Abbreviated ger.

from the GNU version of the Collaborative International Dictionary of English.

• noun A kind of verbal noun, having only the four oblique cases of the singular number, and governing cases like a participle.
• noun (AS. Gram.) A verbal noun ending in -e, preceded by to and usually denoting purpose or end; -- called also the dative infinitive; as, “Ic hæbbe mete tô etanne” (I have meat to eat.) In Modern English the name has been applied to verbal or participal nouns in -ing denoting a transitive action; e. g., by throwing a stone.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun grammar A verbal form that functions as a verbal noun. (In English, a gerund has the same spelling as a present participle, but functions differently.)
• noun grammar In some languages such as Italian or Russian, a verbal form similar to a present participle, but functioning as an adverb. These words are sometimes referred to as conjunctive participles.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a noun formed from a verb (such as the `-ing' form of an English verb when used as a noun)