What's the "een" in Halloween?
early 15c., "repudiation," from Late Latin repulsionem (nominative repulsio) "a repelling," noun of action from past participle stem of repellere (see repel). Meaning "action of forcing or driving back" is attested from 1540s. Sense of "strong dislike" is from 1751.
repulsion re·pul·sion (rĭ-pŭl'shən)
The act of repelling or driving apart.
A feeling of extreme dislike.
The tendency of particles or bodies of the same electric charge or magnetic polarity to separate.