1. sealion - Noun
2. sealion - Verb
sealion (third-person singular simple present sealions, present participle sealioning, simple past and past participle sealioned)
(Internet slang, derogatory) To intrude on a conversation with disingenuous questions in an attempt to engage in unwanted debate as a form of harassment.
(uncommon) Alternative form of sea lion
(Internet slang, derogatory) One who engages in sealioning.
Source: en.wiktionary.org