undertak
/ˈʌndəˌteɪk/Definitions
1. noun
the act of taking on a commitment or responsibility, especially a difficult or solemn one
“After a long period of contemplation, she made the undertak to pursue her lifelong dream of becoming a writer.”
2. verb
to take on or undertake a responsibility or task
“He undertak the challenge of hiking the entire Appalachian Trail within a year.”