What is the meaning of Hopping?

hop picking, the practice of picking hops; for Londoners a holiday period working in the hop gardens of Kent.

The addition of hops during the production of beer as a flavouring agent

present participle and gerund of hop

The act of one who, or that which, hops; a jumping, frisking, or dancing.

A shift from one energy-state to another by an electron in an atom.

That uses hopping for locomotion.

Of a location, crowded with people.

Source: wiktionary.org