undertake

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To take upon oneself; decide or agree to do: undertake a task.
2. v. To pledge or commit oneself: undertake to care for an elderly relative.
3. v. To set about; begin.
4. v. Obsolete To accept combat with.
5. v. Archaic To make oneself responsible. Used with for.

Century Dictionary and Cyclopedia

1. To take on one's self; often, to take formally or expressly on one's self; lay one's self under obligations or enter into stipulations to perform or execute; pledge one's self to.
2. To engage in; enter upon; take in hand; begin to perform; set about; attempt; essay.
3. To warrant; answer for; guarantee; affirm: especially with a following clause.
4. To take in; hear; understand; have knowledge of. To assume, as a character.
5. To engage with; have to do with; attack.
6. To have the charge of.
7. Synonyms and Essay, Endeavor, etc. See attempt.
8. To take up or assume any business, responsibility, or venture.
9. To promise; be bound; warrant; answer for something; guarantee.
10. Specifically To manage funerals, and arrange all the details for burying the dead.

Wiktionary

1. v. transitive To take upon oneself; to start, to embark on (a specific task etc.).
2. v. intransitive To commit oneself (to an obligation, activity etc.).
3. v. informal to overtake on the wrong side.
4. v. archaic, intransitive To pledge; to assert, assure; to dare say.
5. v. obsolete, transitive To take by trickery; to trap, to seize upon.

GNU Webster's 1913

1. v. To take upon one's self; to engage in; to enter upon; to take in hand; to begin to perform; to set about; to attempt.
2. v. Specifically, to take upon one's self solemnly or expressly; to lay one's self under obligation, or to enter into stipulations, to perform or to execute; to covenant; to contract.
3. v. Hence, to guarantee; to promise; to affirm.
4. v. obsolete To assume, as a character.
5. v. obsolete To engage with; to attack.
6. v. obsolete To have knowledge of; to hear.
7. v. obsolete To take or have the charge of.
8. v. To take upon one's self, or assume, any business, duty, or province.
9. v. obsolete To venture; to hazard.
10. v. To give a promise or guarantee; to be surety.

WordNet 3.0

1. v. accept as a challenge
2. v. enter upon an activity or enterprise
3. v. accept as a charge
4. v. enter into a contractual arrangement
5. v. promise to do or accomplish