The Collaborative International Dictionary
jocoserious
jocoserious \jo`co*se"ri*ous\ (j[=o]`k[-o]*s[=e]"r[i^]*[u^]s),
a. [Jocose + serious.]
Mingling mirth and seriousness.
--M. Green.
Wiktionary
jocoserious
a. Simultaneously jocular and serious; mixing mirth with serious matters. alt. Simultaneously jocular and serious; mixing mirth with serious matters.