The adjective Victorian is used to described something from the period of the reign of Britain’s Queen Victoria. And, as Victoria was on the throne for more than 60 years, from 1837 to 1901, the term is also used to describe things from the 19th century in general.
The word is used to describe a wide variety of items, such as Victorian authors or Victorian architecture or even Victorian clothing and fashion. But in its most common usage the word is used to describe social attitudes, implying an emphasis on moral rigidity, priggishness, and prudery.
Queen Victoria herself was often perceived as being overly serious and possessing little or no sense of humor. This was due in part to her having been widowed at a relatively young age. The loss of her husband, Prince Albert, was devastating, and for the rest of her life she wore black mourning clothes.