Extensive and Longest

Extensive adjective - Having considerable extent.

Longest and extensive are semantically related In some cases you can replace term "Longest" with "Extensive", this adjectives are similar.

Nearby Words: extend, extension, extensively, extensible, extender

Longest adverb - For the most time.

Extensive and longest are semantically related in extended in space or time topic. Sometimes you can use "Extensive" instead an adjective "Longest".