One with booster leaves Zoom lecture (6)

I believe the answer is:

rocket

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

'zoom lecture' is the definition.
'rocket' can be an answer for 'zoom' (I've seen this in another clue). I am unsure of the 'lecture' bit.

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for rocket that I've seen before include "Projectile firework" , "Salad vegetable" , "Shoot upwards" , "go fast" , "Soar" .)

I've seen this clue in The Independent.

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