Gerund functioning as an uncountable noun denoting the act or instance of wriggling.
wrigglinggerund / present participle Used attributively as the present participle of ‘wriggle’; tagged more precisely as ADJECTIVE_PRESENT_PARTICIPLE.
The wriggling worm was difficult to catch.
Извивающегося червя было трудно поймать.
The child was wriggling in his seat during the long car ride.
Ребенок корчился на своем месте во время долгой поездки на машине.