Greeting an OAP roughly, a youngster may be showing it

Wikipedia Word definitions in Wikipedia
The name generation gap may refer to: Generation gap : a term referring to differences between people of a younger generation and their elders Generation gap (pattern) : a pattern for modifying or extending generated code Generation Gap (TV series) : 2004 ...

Wiktionary Word definitions in Wiktionary
n. A disconnect between members of one generation and members of the next based on the later generation developing habits, attitudes, and preferences inconsistent with the experience of the former.

Longman Dictionary of Contemporary English Word definitions in Longman Dictionary of Contemporary English
noun EXAMPLES FROM CORPUS ▪ He tells me that they had a discussion in school about the generation gap . ▪ It seemed that he had a foot planted firmly on both sides of the generation gap . ▪ The generation gap here was too wide. ▪ The generation gap is another ...