longueur

pitkästyttävä hetki A lengthy passage in a dramatic or literary work, especially a dull or tedious one; a period of boredom.
2002, (w), The Great Nation, Penguin 2003, p. 30:

He cultivated the aura, if not quite of the Anti-Christ, at least of an Anti-Sun King, discountenancing his uncle and shocking the dévots by preferring the intimacy and informality of a clique of drinking companions to the formal longueurs of the courtly round ....