'accelerando' definitions:

Definition of 'accelerando'

adverb

With increasing speed; "here you must play accelerando"

adjective

Gradually increasing in tempo

noun

A gradually increasing tempo of music; "my ear will not accept such violent accelerandos"

From: GCIDE

increasing \increasing\ adj.
1. becoming greater or larger; as, increasing prices. [Narrower terms: {accretionary ; {augmenting, augmentative, building ; {expanding ; {flared, flaring ; {growing ; {incorporative ; {lengthening ; {maximizing ; {multiplicative ; {profit-maximizing ; {raising ; {accretive ; {rising ] decreasing [WordNet 1.5]
2. same as growing, 1. [prenominal]
Syn: growing(prenominal), incremental. [WordNet 1.5]
3. (Music) increasing in some musical quality. Opposite of decreasing. [Narrower terms: {accelerando ; {crescendo ] [WordNet 1.5]