Found 2 items, similar to infectiously.
English → English (WordNet) Definition: infectiously infectiously adv : in a contagious manner; “she was contagiously bubbly” [syn: contagiously]
English → English (gcide) Definition: Infectiously Infectiously \In*fec"tious*ly\, adv. In an infectious manner. --Shak. [1913 Webster]