Trespass right inside bus, following directions (8)

I believe the answer is:

encroach

I'm a little stuck... Click here to teach me more about this clue!

'trespass' is the definition.
(I know that encroach is a more specific form of the action the trespass)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for encroach that I've seen before include "'Trespass, infringe (8)'" , "Enter upon another's property or rights" , "Advance gradually (beyond expected limits)" , "Advance beyond proper limit" , "Advance beyond the usual limit" .)

I've seen this clue in The Daily Express.

Want a hint initially instead of a full solution? Install my app