very long, and often too long, in time or size lengthy delays the lengthy process of obtaining a visa a lengthy explanationWord Familylong adjective adverblength nounlengthy adjectivelengthen verbExtra examples After a fairly lengthy delay, we were able to continue. Agreement was finally reached after very lengthy discussions. A court case will be expensive and lengthy. I had to go through the lengthy process of obtaining a visa. There is a lengthy summary of the discussions in his diary.