es·ti·ma·tion 
/ˌɛstəˈmeɪʃən/ noun
plural es·ti·ma·tions /ˌɛstəˈmeɪʃən/ noun 1 [singular] formal : a judgment or opinion about something
▪ My estimation of his films was never very high. [=I never thought his films were very good] ▪ This is not, in my estimation, an efficient use of our resources. ▪ She went down in her supporters' estimation after she voted against the plan. 2 a [noncount] : the act of judging the size, amount, cost, etc., of something : the act of estimating something
▪ Planning the project requires careful cost estimation. ▪ By his own estimation [=estimate] he had wrecked six different cars.
b [count] : a guess about the size, amount, cost, etc., of something
▪ My estimation [=(more commonly) estimate] of the amount of materials we needed was wrong.
▪ My estimation of his films was never very high. [=I never thought his films were very good] ▪ This is not, in my estimation, an efficient use of our resources. ▪ She went down in her supporters' estimation after she voted against the plan.
▪ Planning the project requires careful cost estimation. ▪ By his own estimation [=estimate] he had wrecked six different cars.
b [count] : a guess about the size, amount, cost, etc., of something
▪ My estimation [=(more commonly) estimate] of the amount of materials we needed was wrong.
