c.1200, "to entrap," in the same sense as O.E.
underniman (cf. Du.
ondernemen, Ger.
unternehmen), of which it is a partial loan-translation, from
under +
take. Cf. also Fr.
entreprendre "to undertake," from
entre "between, among" +
prendre "to take." The
under in this word may be the same one that also may form the first element of
understand. Meaning "to accept" is attested from c.1250; that of "to take upon oneself, to accept the duty of" is from c.1300.
Undertaking "enterprise" is recorded from c.1425.
[uhn-der-teyk] 
verb, -took, -tak⋅en, -tak⋅ing.
dərˈteɪk