lag

Refers to the delay between a cause and its effect.

A common alternative to 'lag far behind', emphasizing the large gap.

To be behind someone or something by a large distance or amount.

An informal way to say 'lag far behind'.

To be significantly behind in progress or development.

To be behind to a worrying or severe degree.

Uncommon by itself. Almost always used in the phrase 'lag well behind' to mean lagging by a large amount.

To move or develop more slowly than others.