in constant agitation; "a seething flag-waving crowd filled the streets"; "a seething mass of maggots"; "lovers and madmen have such seething brains"- Shakespeare
a note that alternates rapidly with another note a semitone above it
the articulation of a consonant (especially the consonant `r') with a rapid flutter of the tongue against the palate or uvula; "he pronounced his R's with a distinct trill"
pronounce with a trill, of the phoneme `r'; "Some speakers trill their r's"
to move in a twisting or contorted motion, (especially when struggling); "The prisoner writhed in discomfort"; "The child tried to wriggle free from his aunt's embrace"