1 PHYSICAL/MENTAL ENERGY (U) the physical or mental energy that is needed to do something: Lou lifted the box without any apparent effort. | take/require effort: It takes a lot of time and effort to get an exhibition ready. | take all the effort out of (=make something much easier) | put a lot of effort into (=work very hard at something): Frank put a lot of effort into the preparations for the party.2 ATTEMPT (C, U) an attempt to do something, especially when this involves a lot of hard work or determination: effort to do sth: My efforts to convince Lucy to return failed.(+ at): Further efforts at negotiation have broken down. | concerted effort (=a strong sincere attempt): Jack has made a concerted effort to improve his behaviour. | through sb's efforts (=because of what someone did): It's only through your efforts that we have managed to raise the money. | in an effort to do sth (=in order to achieve something): They've been working night and day in an effort to get the bridge ready on time.3 make an effort (to do sth) to try hard to do something, especially something you do not want to do: I know you don't like her, but you could make an effort to be polite. | make every effort (=use a lot of effort and try different ways): Every effort is being made to deal with the issues you raised at the last meeting.4 an effort of will/imagination/concentration the determination needed to do something: She dismissed the painful memory with a deliberate effort of will.5 be an effort to be difficult or painful to do: I was so weak that even standing up was an effort. | Would it be too much effort to get it yourself?6 a good/bad/poor etc effort something that has been done well, badly etc: Not a bad effort for a beginner!
Longman dictionary of contemporary English. 2004.