Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
āvulsĭo (āvol-), ōnis, f. [avello]; in gardening, t. t., a plucking off, tearing off of the branches of a tree: Aut semine (arbores) proveniunt aut plantis radicis aut propagine aut avolsione, Plin. 17, 10, 9, § 58; 17, 13, 21, § 98.