Sentence:  Over time, the <WSD>silly season</WSD> in Catholic liturgy that peaked in the 1970s—"clown" masses (with the priest vested as Bozo or somesuch), free-for-all prayers that ignored the prescribed rite, dreadful pop music, inept "liturgical dance," a general lack of decorum—began to recede. 
Meaning of the word marked with <WSD> tags:  A period of time, as during a holiday season or a political campaign, in which the behavior of an individual or group tends to become uncharacteristically frivolous, mirthful, or eccentric.