A large piece of faecal matter. Often the effect of a long toilet session. A Heaphy often gives off the initial impression of being a one-wipe-wonder...but infact turns out to be a titanic, time-consuming painful ordeal.
In 1978, three men died from a Heaphy....doctors said that due to a combination of ruptured sphincter muscles and the loss of the will to live they topped themselves, knowing that life would never be the same
In more recent usages, the word Heaphy is made when actually doing a poo.
1) I just went and had a heaphy...it was fucking terrible.
2) I thought i was about to have my first born, but it turned out to be a Heaphy.
3) (While pooing). "HEEEEEEAAAAAAAPPPPPHHHHHYYYYYYYYY"