"It is clear from this site that the verb to trump has been used extensively across Britain to refer to the breaking of wind. It is especially the case in the North, in Wales and certainly in Norfolk, when I was a child in the 1950s. This use is confirmed by the OED. However though it is therein described as vulgar my own experience is that it was a term encouraged by parents as a means of avoiding the far less socially salubrious fart."

http://english.stackexchange.com/questions/264355/in-what-english-speaking-communities-does-trump-refer-to-the-breaking-of-wind