WordNet sense 1 (a personal pronoun compounded with -self to show the agent's action affects the agent):

reflexive pronoun

WordNet sense 2 (without volition or conscious control):

automatic, reflex, reflex

WordNet sense 3 (controlled by the autonomic nervous system; without conscious control):

involuntary

WordNet sense 4 (referring back to itself):

self-referent

WordNet sense 5 (directed or facing toward the back or rear):

backward