Acespike is an asexual orientation on the asexual spectrum. It is defined as someone who usually feels no sexual attraction, but occasionally has rare, sudden, and intense spikes of sexual attraction for a short amount of time, before returning, just as suddenly, to one's normal amounts of asexuality.
Acespike can be a sexual orientation on its own or can combined with other orientations. For example, one could be acespike and homosexual, meaning that when one does experience sexual attraction it's exclusively towards individuals of the same gender.
The romantic counterpart to acespike is arospike. Being both acespike and arospike makes someone aroacespike. The opposite of acespike is ace-jump.