1) to shake off so that something adhering shall fall
1a) by this symbolic act a person, expresses extreme contempt for another and refuses to have any further dealings with him
1b) to shake off for (the cleansing of) one's self
Part of Speech: verb
From G1537 and τινάσσω tinassô (to swing); to shake violently: - shake (off).
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root ἐκτινάσσω; click on the second column to search for that grammatical form of the root ἐκτινάσσω; click on the third column to search for that word and grammatical form; click on the total to search for the root ἐκτινάσσω.