Icchantika literally means one who desires. It refers to a person who is destitute of good conditions that lead to favorable results, such as awakening and liberation. Hence, it is also glossed as one deprived of merits. The major doctrinal debate over this concept is whether all sentient beings, including icchantikas, are capable of achieving the Buddhahood. In the view of the Vijñaptimātra School (alias the Mind-only School), for example, icchantikas are devoid of proper conditions in nature, therefore would never achieve the final goal. Whereas, in Tathāgatagarbha and Avataṃsaka traditions, all sentient beings are born with the nature of a Buddha, which only anticipates to manifest (at some point). Generally speaking, the former standpoint takes icchantika as innate, while the latter understands it as a temporary status.

I have often proclaimed the universality of the Buddha-nature in all sentient beings, including icchantikas (literally one who is subject to great desire, hence according to certain schools should be bereft of all the possibilities to achieve Buddhahood). Icchantikas, though devoid of any meritorious deeds accumulated so far throughout their past lives, still possess the Buddha-nature and thus will be able to engage in the wholesome activities in the future. (Sutra of the Great Nirvana)

Taking scriptures and commentaries into consideration, there are three types of icchantikas… The first type refers to icchantikas out of compassion who are ready with the conditions to emancipate but do not realize it since they vowed to liberate all beings before they realize the nirvana. The second type refers to icchantikas endowed with the Buddha-nature but without proper deeds to realize the Buddhahood, who could expect the result facilitated by the power of a Buddha while lack of sufficient conditions. The third type refers to icchantikas deprived of the Buddha-nature, who have neither the conditions nor the result-to-be and are destined to follow the two inferior paths of śrāvaka and pratyekabuddha. (ShiKuiji: A Commentary on Collected Commentaries to the Perfection of Consciousness-only)