Longman Dictionary of Contemporary English - undersubscribe

~ v be undersubscribed if an activity, sale, service etc is undersubscribed, not many people want it undertake, v past tense undertook past participle undertaken formal 1 to accept that you are responsible for a piece of work, and start to do it  (She undertook full responsibility for the new changes.) 2 undertake to do sth to promise or agree to do something  (He undertook to pay the money back in six months.)