Exact is the opposite of Estimate. Estimate is a type of Respect. Respect is related to Expression. Expression is related to Word. 
Long is similar to Tall. Tall is similar to Difficult. Difficult is related to Complicated. 
Exact <--Antonym--> Estimate --IsA--> Respect <--RelatedTo--> Expression <--RelatedTo--> Word 
Long <--SimilarTo--> Tall <--SimilarTo--> Difficult <--RelatedTo--> Complicated 