at irregular intervals at random brokenly by catches by fits by jerks by snatches capriciously desultorily disconnectedly discontinuously eccentrically erratically fitfully flutteringly haltingly in snatches in spots inconstantly intermittently irregularly lurchingly nonuniformly off and on patchily quakingly quaveringly quiveringly roughly saltatorily shakily shudderingly spasmodically sporadically spottily tremblingly tremulously uncertainly unevenly unmethodically unpredictably unrhythmically unsteadily unsystematically variably waveringly whimsically wobblingly